The Future of Naval Aviation

MIT Security Studies Program

TheThe FutureFuture ofof NavalNaval AviationAviation

Owen R. Cote Jr. Associate Director M.I.T. Security Studies Program

This report is a product of the M.I.T. Security Studies Program. It is the sixth in a series authored by Owen Cote and devoted to the subject of the U.S. Navy in the future security environment.

This series of reports is dedicated to the late Vice Admiral Levering Smith, U.S.N., the technical director of the Navy’s fleet ballistic missile program during the development of Polaris, and from 1965 to 1977, its director.

The author would like to thank Admiral John Nathman, Vice Admiral Mark Fitzgerald, Rear Admiral Thomas Kilcline, and Malcolm Taylor for their support for this project, and Jeanne Abboud and Harlene Miller for their help in producing this report. It, along with other MIT/SSP reports, is available at http://web.mit.edu/ssp/

Contents

Executive Summary | 7

The Future Security Environment | 15

Sea Shield Past, Present, and Future | 35

The Revolution in Sea Strike | 55

Conclusion | 75

Notes | 78 When concentrated, multiple carriers are now able to produce effects ashore that would formerly have required many more wings of tactical aircraft operating from local bases in the region, while at the same time protecting the sea base and extending that shield ashore. Executive Summary

ODAY, ALONGSIDE ITS ALL IMPORTANT OPERATIONS in direct support of the Global War on Terror, naval aviation also continues its now 60 year commitment to shap- Ting the maritime and littoral environment through persistent forward presence. In the longer term, naval aviation is also adapting to a series of geopolitical revolutions which will dramatically increase the future demand for a secure sea base capable of projecting dominant power ashore in wartime against the full spectrum of possible opponents. It is adapting to these demands by exploiting technologies and operational practices developed in the last decade that will greatly increase its ability to surge and concentrate forces rapidly; protect the sea base from new air, surface, and undersea threats; and find, identify,locate, track, and strike mobile as well as fixed targets ashore, under all weather conditions, and in timely enough fashion to produce the desired effects.

Formal Alliances Provide Predictable Access, Informal Coalitions Do Not 5 The main source of new demands on naval aviation is the decline in secure and predictable access to overseas bases resulting from the shift in strategic focus away from the central front of Europe to the long Eurasian littoral, which extends from the Mediterranean to the Yellow Sea. Along this arc, the United States lacks and is unlikely to recreate the tight, long term alliance relationships which were a hallmark of the Cold War, from which flowed assured access to bases ashore. Instead, it faces a security environment in which ad hoc coalitions will form to solve specific problems; access to bases ashore will be episodic and unpredictable in advance of conflict, as was the case with Turkey in the run up to Iraqi Freedom; and the freedom to operate from such bases during conflicts can be suddenly withdrawn, as happened more recently in Uzbekistan.

Distributed Ground Forces Require Persistent, Distributed Air Support Today’s ground forces, operating in dispersed fashion, far from sustaining bases, in extremely austere environments, and in units ranging from section to brigade — rely on air forces for combat power more than they did during the Cold War. In particular, they depend on air forces for timely attacks against targets that emerge quickly and unpre- dictably in meeting engagements, and which must also be destroyed quickly.They also depend on air forces to detect, identify,and destroy larger concentrations of enemy forces moving to contact with elements of the distributed ground force. A sea base allows a supporting air force to operate in distributed and persistent fashion, while retaining the ability to concentrate quickly and bring dominant power to bear. The Sea Shield Must Be multiple smaller force packages in dispersed Dominant If the Sea Base fashion that retain robust shield and strike Is To Be Effective capabilities for use against more common mid- and low-level threats. In order for the sea base to play a central role in support of engaged forces ashore, it must be provided a dominant defensive shield, and The Spectrum From Presence must be able to project that shield ashore. A to Major Combat shield for the sea base preserves the access necessary for expeditionary maneuver war- For many years, the primary metric for fare against both existing and emerging mil- assessing Naval Aviation capabilities has itary threats. When anti-access threats are alternated between peacetime presence and present, the sea base will need to be able to wartime surge requirements. In the last play offense and defense at the same time, decade, carrier forces have operated simulta- and do so with absolute reliability, even neously along the entire spectrum from when anti-access threats appear relatively peacetime to major war. For example, since low, and the temptation to trade sea shield 1990, Naval Aviation has maintained a near capabilities for more sea strike will exist. continuous 1.0 presence in the Arabian Gulf, along with a forward-deployed carrier in Adapting Japan and a frequent presence in the Mediterranean. From this peacetime posture 6 Naval aviation is adapting to the demands of a forward deployed carrier has often been the new security environment across all its flexed in response to crises in places like the mission areas and against the full spectrum of Arabian Gulf and the Balkans, trading pres- threats. At the most aggregate level, naval ence in one theater for another. In other aviation is developing a force structure and cases, pairs of carriers have been concentrat- operating tempo which maximizes its con- ed, as occurred off Taiwan for one month in tribution across the spectrum of conflict, 1996, and in the Indian Ocean for seven whether measured in terms of time or threat months in 1997-98. During both Operation level. In terms of time, this involves presence Enduring Freedom (OEF) and Operation and shaping operations in peacetime, crisis Iraqi freedom (OIF), as many as six carriers response operations designed either to deter at one time were deployed to support com- conflict or to maximize early arriving combat operations, and as many as eight total bat power should deterrence fail, and large carriers were employed over the course of scale surge operations whose purpose is the the conflict. dominant application of sea-based power Metrics based only on peacetime pres- projection with an eye to the rapid and deci- ence or wartime surge requirements fail to sive defeat of the opponent. In terms of capture the complex requirements generated threat level, this involves the development by a world in which presence, crisis response, and insertion of rapidly evolving technolo- and major surges are all necessary – some- gies into sensors, weapons, and networks. times simultaneously.This makes force plan- The platforms which deploy these technolo- ning more difficult, because the planner gies will be capable of concentrating to cannot focus on a single metric, such as dominate and defeat the high end threats, needing five carriers to maintain one in the while also remaining prepared to operate Indian Ocean, or twelve to be able to surge eight. As it is more realistic to assume Naval sance aircraft (MPRA) have been the major Aviation will be asked to provide all three platform-related aspects of the carrier aviation functions, as well as others not yet imagined, modernization strategy. a carrier force that is able to sustain that more complex burden is needed. The force that is providing presence or The Value of Robust AEW conducting the Global War on Terror today Any advanced, integrated air defense system will often be the first to arrive in a crisis relies on a fleet of airborne early warning response or major combat scenario tomor- (AEW) aircraft with powerful radars provid- row. Combat power applied in the first days ing a persistent, high altitude view of the of a crisis response or major combat scenario battlespace. Only upon this base can an outer is like the “golden hour” in combat medi- area defense be erected that aspires to keep cine, because it produces relatively more attackers well outside range of their targets, deterrent or warfighting effect than a larger so they can be killed before they can launch amount of combat power that arrives later. their weapons. Without AEW, defenders The Navy has historically avoided tailoring cede enormous amounts of battlespace to its deployed forces to the lower threat envi- their attackers, decrease warning time, elim- ronment in which they often find them- inate multiple kill opportunities, and place selves operating; instead, it deploys forces primary reliance on difficult, close in, time that are prepared for the full spectrum of critical engagements against arrows rather combat. For example, when Iraq invaded than archers. If one looks around the world 7 Kuwait in August 1990, the Independence on land, one can identify those few countries (CV-62) battle group was in the Indian that actually seek to keep opponents out of Ocean, ready to respond, as was the their air space by their AEW aircraft. At sea, Enterprise (CVN-65) battle group following the presence or absence of carrier-based the 11 September 2001 terrorist attacks on AEW is even more decisive. Airborne early American soil. warning also determines the ability of the sea base to project power ashore in the face of all but the most minimal anti-access Technology and the Spectrum threats.Thus, it is one of the main determi- of Threat nants of whether a sea base can play offense Naval Aviation must also ensure that its forces and defense at the same time. have the capabilities needed against the full spectrum of threats.This is a more technolog- No Substitute For Range in ically intensive process than force planning, Carrier Aviation and it has been the object of a decade-long Naval Aviation recapitalization strategy that is The long range, sea-based strike fighter, with about to reach fruition. Advanced airborne its ability to engage in multiple, simultane- early warning (AEW) aircraft; increased per- ous, and dispersed engagements 24 hours a sistence and range for strike fighters; modern- day, is a key enabler of power projection ized airborne electronic attack (AEA) ashore. Both OEF and OIF have proven the platforms; advanced surface, undersea, and inestimable value of sea-based strike fighters mine warfare helicopters; and long range, per- as a distributed, timely source of fires over sistent, land-based maritime patrol reconnais- the battlefield, both against fleeting high value targets, and in support of blue ground report of a suspicious merchant ship, or an forces operating in dispersed fashion on important signals intelligence collection non-linear battlefields. Adding range to opportunity. The maritime patrol fleet is today’s relatively short-legged naval strike evolving into a triad of more capable assets— fighters through enhanced organic mission the P-8A Multimission Maritime Aircraft, tanking and greater internal fuel capacity can the Aerial Common Sensor, and the Broad expand the maneuver space of the sea base Area Maritime Surveillance Unmanned without compromising the reach or persis- Aerial Vehicle—that are an important ele- tence of its main striking arm; increase the ment in Naval Aviation’s recapitalization. overland persistence and coverage of that Deployed in small expeditionary contingents striking arm from the same maneuver space; at the strategic approaches to and operating or some combination of the two.The greater locations along the Mediterranean-Indo- the range extension, the more flexibility and Pacific arc, the new maritime patrol triad capability result, allowing the commander at will provide improved surface surveillance, sea to maneuver and operate his sea base in antisubmarine warfare, antisurface warfare, such a way as to task-optimize his force and multisource intelligence collection. along the full spectrum of conflict. Multimission Helicopters The Need for AEA Is Not Maritime patrol assets need to be comple- 8 Going Away mented by a more distributed force capable Airborne electronic attack (AEA) is a key of quickly responding to its cues; identifying enabler of strike operations by non-stealthy potential contacts as friend, foe, or neutral; aircraft against even modest air defenses, and and either tracking the contacts or destroy- is central to any concept of air operations ing them, depending on the circumstances. against more advanced air defenses. Although The specific sensors, and weapons used to this is one of several possible future roles for acquire and prosecute contacts in surface UCAV, an AEA platform based on a long warfare, undersea warfare, and organic mine range strike fighter is necessary in the mid warfare missions will vary, but because they term.The range and persistence of AEA plat- will often be deployed and operated from forms must be equal or even better than the the same platforms and in the same littoral strike fighters they support. battlespace, there is a tremendous premium on combining them on the same multimission helicopter when possible. Land-Based Maritime Patrol Aircraft Long range, persistent, land-based maritime New Capabilities and patrol aircraft provide the only way for a Challenges dominant naval power to maintain a contin- New sensors, networks, and weapons, along uous presence and surveillance throughout with new platforms, will introduce some the vast ocean and littoral spaces over which radically new capabilities for naval aviation. it must exercise control. They often provide For example, there are already emerging the most timely means of response, whether technologies that will enable through the to a fleeting undersea acoustic contact, a weather attacks against mobile ground targets.There are also areas where the technol- of targets that are actually moving will also be ogy is less mature and where naval aviation developed and deployed. One option will be faces significant challenges, such as in under- to use bilateration or trilateration in a net- sea warfare. work of airborne radars to reduce the errors in azimuth intrinsic to single radars when they are tracking moving targets, and to use a Eliminating the Weather data link to give a weapon in flight constant Sanctuary for Mobile Targets updates of the moving target’s changing posi- Radars suffer little or no interference from tion. Another option will be to improve ter- weather but, unlike in air-to-air combat, it minal seekers on weapons to the point where has proven impossible to this point to use they can acquire, recognize, and home on a air-launched, radar-guided weapons against moving vehicle after the less accurate cueing combat vehicles on the ground beyond provided by a single tracking radar. ranges of five kilometers or so. That con- Certainly,substantial limits will remain on straint has preserved a sanctuary from air what ground targets can be detected, identi- attack for mobile targets when clouds lie fied, and attacked from the air, but with the between the attacker and the target, because weather sanctuary for combat vehicles great- other means of attacking mobile targets have ly reduced, an opponent’s freedom to con- historically relied on visual acquisition of the centrate and maneuver will also be greatly target. GPS-guided weapons solve this prob- reduced, enabling the distributed, non-linear lem when the target’s location is precisely approach to battle that U.S. ground forces 9 known, but the vehicles which comprise an will increasingly adopt. opposing ground force often move frequently and in unpredictable fashion, and combat aircraft do not currently have the ability to Providing a Dominant Defense target GPS-guided weapons in real time. of the Sea Base In the near to mid term, strike fighters In strike operations ashore, naval aviation will become capable of targeting mobile tar- will often be part of a joint team, but when gets temporarily at rest because the aircraft’s defending the sea base from attack, the Navy own synthetic aperture radar processing will will often be on its own.This is not a prob- soon be capable of comparing an organical- lem in much of the world because most ly-generated SAR image with an onboard countries have no capability to project database of geo-registered SAR imagery power out to sea. Of those countries of con- automatically and in real time. Alternatively, cern that pose a threat to the sea base, many toward the same end, it will soon be possible do so only with ground or small boat- to use an organically generated SAR image launched, anti-ship missiles and mines, limit- as a scene-matching template for a weapon ing both their reach and their effectiveness. with an infrared terminal seeker, achieving Some more capable potential adversaries add the same goal of targeting through weather a missiles launched by aircraft or major surface mobile target temporarily at rest, while in combatants and non-nuclear submarines this case, also reducing or eliminating deploying mines, torpedoes, and, in a few reliance on GPS. cases, antiship missiles. At the highest end of In the mid to longer term, one of several the spectrum, the sea base may face an oppo- possible approaches to the all weather attack nent with over-the-horizon sea surveillance capabilities extending as far as 1000 miles for Make Opposing Submarines cueing antiship attacks by long range, termi- Pay For Their Inevitable nally-guided, ballistic missiles and/or non- Indiscretions nuclear submarines with air independent propulsion (AIP). In the undersea environment the challenges Though formidable compared to the are different. Here, sensor performance is norm in today’s world, these potential anti- limited, reducing detection ranges, and access threats do not equal those the Navy making wide area surveillance a more asset- faced down during the Cold War. On the intensive endeavor. Furthermore, unlike other hand, because the Navy will be asked nuclear submarines, which usually produce to play a much larger power projection role a continuous acoustic signature, the best relative to land-based forces than was the detection opportunities against non-nuclear case during the Cold War, the Navy’s sea submarines are both episodic and difficult shield capabilities must dominate the high to classify. On the other hand, there is a end anti-access threat. The path to domi- close correlation between the steps a sub- nance in this mission area varies between the marine needs to take in order get into posi- air, surface, and sub-surface environment, tion to attack a target, and the operational and the consequences for naval aviation vary indiscretions which provide the best detec- as well. tion opportunities for ASW forces. Therefore, contacts must be prosecuted and reliably classified as quickly as possible 10 Shoot Archers Not Arrows before they disappear back into the cluttered background as an unknown contact. On the surface and in the air, surface com- This puts a premium on ASW platforms batants and aircraft will be detected long that can be deployed in numbers and dis- before they can target and launch their mis- tributed throughout the sea base, close a siles against the sea base because of powerful, potential contact quickly, and deploy a fully networked surveillance radars such as menu of high quality acoustic and non- Advanced Hawkeye and the Broad Area acoustic sensors to reacquire and identify Maritime Surveillance (BAMS) system. Even the contact, classifying it as a false alarm, or if missiles are successfully launched, strike trailing and/or attacking it. fighters with AESA radars, as well as extended range Standard missiles, will give the sea base a greatly extended battlespace in which Get Back In the Counter- to engage them, allowing multiple intercept Surveillance Business opportunities against each incoming missile. Technology will improve this picture further Finally,in the longer term, against more for- when it allows better long range combat midable anti-access threats, the Navy will identification and, in the event some missiles need to get back into the business of deny- leak through, improved passive ships’ self ing its opponent a reliable ocean surveillance defense systems alongside the active systems capability.The worst potential threats to the already planned. sea base emanate from missile attacks launched from outside the sea base’s defenses, but they therefore also demand that the weapon be launched from well beyond line- of-sight to its target. This in turn requires years of the war in the Pacific. Such a force, effective over-the-horizon surveillance, clas- operating in dispersed or concentrated fash- sification, and tracking from other sources, ion, will be the key to meeting the greater and that these sources also provide cueing to demands on naval aviation in the new secu- weapons timely and accurate enough for rity environment described above. their terminal seekers to reacquire and lock For example, a force of six carriers onto the correct target and complete the includes some 300 strike fighters, 30 E-2s, engagement. Alongside the added reach of and 100 multimission helicopters, all operat- such a centralized, networked, anti-access ing in mutual support of both each other system come potential new vulnerabilities at and expeditionary forces ashore.As President each step of the engagement sequence, as the Bush noted at Annapolis recently, since Soviet Navy learned during the Cold War. Desert Storm, the number of targets ashore that a single carrier is capable of destroying The Force of the Future in a single day has tripled.This means that a forward deployed carrier’s capability to The United States has long understood the influence events during the “golden hours” value of single, full spectrum carrier battle early in a contingency have been greatly groups forward deployed in peacetime. It has enhanced. It also means that when concen- also understood the value of concentration trated, multiple carriers are now able to pro- in wartime when necessary; witness the duce effects ashore that would formerly have multi-carrier operations practiced off the required many more wings of tactical aircraft 11 coast of North Vietnam and those envisaged operating from local bases in the region, by the Cold War maritime strategy.But it has while at the same time protecting the sea been many years since concentrations of car- base and extending that shield ashore. rier aviation were in a position to be so The relative value of Naval Aviation as a unambiguously dominant in the power pro- guarantor of national security and an instru- jection role, both in terms of its freedom to ment of national will has never been greater maneuver in the face of opposing defenses, than in today’s post-9/11 strategic landscape. and in terms of its ability to produce decisive From the Pacific campaigns of World War II effects ashore. If one combines the effects of through the complete battlespace dominance the precision weapons revolution (multiple demonstrated during Operations Enduring kills per sortie) with the high sortie rates Freedom and Iraqi Freedom, Naval Aviation possible on a large deck carrier, and then continues to evolve as a decisive force concentrates up to five or six of those carri- through ongoing incorporation of advanced ers in one theater of operations, one is technology. The necessary investments must deploying a combat force analogous in capa- be made to sustain this preeminent force to bility to the Fast Carrier Task Forces ensure the United States’ continued access employed to devastating effect in the last two and ability to shape world events. Persistent surveillance, whether manned or unmanned, land or sea-based, is the foundation for success in all mission areas in the new security environment. The Future Security Environment

he long term security environment require a new continental commitment. is obviously less predictable than the Rather, should there be such a challenge, it Tnear term, and it is therefore more dif- will likely arise in a maritime context.This is ficult to make specific assumptions about its because nuclear weapons and political geog- likely characteristics. But assumptions can be raphy conspire to make significant landward made and trends identified in several areas. expansion by Russia, China, India, or the First, it is unlikely that the United States will European Union at the expense of each have to make a major continental commit- other all but unthinkable. ment in order to preserve a balance of power During the Cold War, Germany’s divi- in Eurasia; second, it will have unpredictable sion and its non-nuclear status made it access to bases along the Indo-Pacific littoral unable to defend itself against Soviet attack where it will most likely need to project alone. The unification of Germany and the power; third, it could face opponents with collapse of the Soviet Union made Germany capabilities ranging across the full spectrum of and Russia much more equal in basic power conflict; fourth, new operational demands potential, and also established a number of 13 will result in more sea basing and a more dis- medium-size buffer states between them. tributed and persistent tactical air force; and Thus, a unified Germany would be much fifth, technology trends will increasingly favor less disadvantaged in a conventional military airborne as well as spaceborne sensor plat- competition with Russia. And Germany’s forms, networking, persistence, decentralized continuing non-nuclear status could evolve execution, and robust, line-of-sight data links. in three directions in the future, none of which would make major war between Major Continental Germany and Russia likely. Commitments on the First, current tensions aside, U.S. nuclear Eurasian Land Mass Will guarantees to Germany in the context of Not Be Necessary NATO might simply continue. Second, the further intensification of European unifica- The key military aspect of the Cold War was tion might substitute for these guarantees via the fact that the United States made a conti- a European-based alternative.Third, and per- nental commitment to Western Europe’s haps least likely, Germany might eventually security.The grand strategic purpose of this develop nuclear weapons of its own, which commitment was to contain Soviet power, would undoubtedly create tensions, but preventing it from uniting the resources of which would in some ways deepen rather the Eurasian landmass. The military expres- than weaken the barriers to major landward sion of this commitment was a large, contin- expansionism, at least by one nuclear power uing peacetime commitment of U.S. ground at the expense of another. forces. It is extremely unlikely that any future The land border separating Russia and threat to the Eurasian balance of power will China has also acquired buffer states such as Kazakhstan and Mongolia, so that the two competition, and will all face competing larger countries abut only in China’s upper pressures to balance or bandwagon against Xinjiang province and more extensively different perceived threats to their own along the border between Manchuria and interests. And unlike the newly independent the Russian maritime provinces. Both of medium powers in Central Europe, these these borders could become future sources powers are not part of any strong, transna- of instability,but these instabilities should be tional security organizations like NATO or constrained both by the fact that China and the EU. Russia are likely to remain major nuclear powers, and by the fact that the vulnerabili- U.S. Alliance Relationships and ties along their land borders should tend to Access to Overseas Bases Will cancel each other out.That is, China is vul- Be Less Formal and More nerable to separatism in Xinjiang province, Unpredictable Than Those That which is near the base of Russian land Obtained During the Cold War power, and Russia is vulnerable to separatism in its maritime provinces, which are The main Cold War alliance relationships near the base of Chinese land power. between the United States and NATO and Finally, India is likely to maintain rough Japan benefited from a basic agreement parity between its nuclear forces and among the parties to each alliance on the China’s,and furthermore, the political geog- threats that justified it, the tools needed to 14 raphy of the subcontinent will continue to oppose those threats, and the essential equal- provide a powerful buffer against invasion ity of national interests and thermonuclear along the entire Indo-Chinese land border. risks at stake for all its members. Although Central Asia and the Indo-Pakistani subcon- the United States dominated each alliance, it tinent are likely to be enormous sources of also committed itself to the most binding of instability, but geography and nuclear security guarantees: the promise to use U.S. weapons make it unlikely that that instabili- nuclear weapons, if necessary,to defend allied ty will provoke a major ground war between territory from attack, whether conventional India and China, and absent such a war, or nuclear. In return for this commitment, events on the ground in this region are U.S. allies granted unprecedented access to unlikely to cause major shifts in the overall bases within their territory and allowed the Eurasian balance of power. United States to station hundreds of thou- The most likely venue of great power sands of troops.The rights of access and oper- competition and even war will, instead, have ational activity granted by each host nation a more maritime focus. China and Japan is were codified in formal status-of-forces one obvious potential conflict dyad, and agreements and were therefore predictable China and India is another.A triangular com- and reliable enough to be assumed as a given petition among all three powers over control in Cold War military planning. of the energy flows from the Middle East and Both alliances were a response to the Central Asia is also possible. The medium Soviet threat, and both continue after its powers that sit astride the key sea routes, such demise, but neither any longer provides the as Singapore, Malaysia, Indonesia, the United States assured access to local bases Philippines, Korea, and of course, Taiwan, near or along the long littoral from the will all have stakes in the outcome of such a Mediterranean to the Sea of Japan.There, a better model for the alliance relationships enjoys good relations with Israel’s largest sup- that will provide such access, when it is porter; it is wealthy state with a small popu- granted, is the U.S.-Saudi relationship. lation that abuts several poorer states with Originally formed early in the Cold War, large and growing populations. The United the relationship grew in importance to both States could solve only some of the Saudis’ the United States and Saudi Arabia after the security problems, while at the same time fall of the Shah appeared to eliminate Iran as exacerbating others, and it was always diffi- a buffer between the Soviet Union and cult for the Saudi monarchy to determine the Persian Gulf oil.Yet the United States gained balance between these two effects of their only limited access to Saudi bases before military cooperation with the U.S. For 1990 in support of its Rapid Deployment example, there is no question that the Saudi Force (RDF), mostly in the form of port regime’s greatest domestic threat comes from visits and pre-positioning of ammunition fundamentalist Islamists, and the U.S. military and other supplies. Iraq’s invasion of Kuwait presence certainly served as a rationalization, resulted in a decision by the Saudi monarchy if not a cause, for claims by Bin Laden and to allow U.S. forces unlimited access, but others that the Saudi regime was failing in its that decision was not made until four days sacred role of protecting the holy cities of after the invasion began, when Iraqi forces Mecca and Medinah from the infidel. were already poised on the Saudi border.i Even before 9/11 and the two wars that After the war, the Saudis allowed U.S. have followed, both the 1997 Report of the combat aircraft to remain deployed, but National Defense Panel and the more recent 15 refused U.S. requests to pre-position a Hart-Rudman Commission report New World brigade set of heavy armor.ii During the Coming discussed why many of the uncertain- decade or so of Southern Watch, those ties that characterized U.S.-Saudi military deployed air forces were put under strict cooperation during the period described above operational restrictions, including a ban on will be endemic in the new security environ- flying any strike sorties from Saudi territory, ment. For example, the latter noted that: even during crises such as Operation Desert Fox in December 1998. iii In dealing with security crises, the 21st Saudi reticence about granting the U.S. century will be characterized more by unrestricted access to its bases continued episodic “posses of the willing” than after 9/11. Though many support missions the traditional World War II–style were flown out of Saudi bases during both alliance systems.The United States will Operations Enduring and Iraqi Freedom, increasingly find itself wishing to form few if any combat missions were. And of coalitions but increasingly unable to course, soon after the assumed completion find partners willing and able to carry of combat operations in Iraq, U.S. forces left out combined military operations.iv Saudi Arabia altogether. Many factors explained this Saudi schiz- When the alliances that produce base ophrenia about U.S. forces, even during the access are episodic and temporary, the access height of their cooperation. The Saudi they produce will be as well. regime is a Sunni feudal monarchy that sits Finally and perhaps most importantly, across a narrow sea from Iran, a Shia funda- those who must consider granting access to mentalist theocracy; it is an Arab state that U.S. forces in the future will do so without the prospect of receiving the security guar- decades, if not sooner. Any country able to antees against both nuclear and convention- sustain a peacetime defense budget of $150 al attack that the United States gave its billion a year or more, possessing a techni- important Cold War allies.This will make it cal/military/industrial complex capable of harder for them to determine whether giv- designing, building, and operating modern, ing U.S. forces access will increase or information technology-laden military sys- decrease their long-term security.For exam- tems, could cause a reprise of some aspects of ple, as the National Defense Panel argued, the Cold War military competition between this might lead to limits on access for U.S. the U.S. and the Soviet Union. China does forces when potential allies face regional appear on a path that would put those capa- rivals armed with weapons of mass destruc- bilities within its reach, and there are cer- tion.v Limits on access are also likely when tainly aspects of China’s geopolitical position potential regional allies face serious conven- that might cause it to embrace that path. tional threats. The main point is that any future conflict This is not to argue that U.S. forces will with a peer competitor is likely to take the gain no access to bases abroad. When faced form of a struggle for control over the Indo- with clear threats to their sovereignty, many Pacific littoral because of the desire of some states will ask for help, and when it is in the power to control and assure access to the seas interests of the United States to respond, its and littoral chokepoints that will continue to forces will be given access. But this access link the world’s primary users of energy to 16 will often come late, after a conflict has its main supply.Given that the United States already begun; it will often be austere, in that Navy now provides that service to the world few preparations will have been made in as a free good, it is ironic that the rise of a advance; and it will often be withdrawn or peer competitor would therefore be as like- sharply limited after the particular conflict ly to result from a retrenchment of U.S. mar- that generated it is resolved. itime power in the Indo-Pacific region as from an overexpansion of that power. Future Military Opponents In general, when maritime hegemony is used to assure rather than suppress free trade, One can imagine three types of military it takes on the character of the trade that it opponents for the United States in the new assures; an exchange in which all achieve security environment; peer competitors in absolute gains larger than they would in the competition for energy resources with the absence of such trade, but in which the U.S.; medium powers that seek or provide largest traders may achieve larger relative nuclear technology: and terrorist groups gains than others.Thus, maritime hegemony, with global reach and their state sponsors. when it is used to assure free trade, is rarely itself the cause of great power conflict, Great Power Opponents because states generally ignore the balance of relative gains from trade unless they are For lack of a plausible alternative, many focus already in a military competition with their on China as a future peer competitor of the potential trading partners. This is a funda- United States. Certainly,it is possible to argue mental difference between naval hegemony that China will be wealthy and technically and military hegemony, defined as the effort advanced enough to play this role within to develop supremacy of land power relative to one’s neighbors, because such supremacy the United States today will be gone or sig- creates the threat of landward expansion.The nificantly reduced. threat of landward expansion by definition involves a threat to the basic sovereignty of Medium Power Opponents the potential victim, and is therefore much more likely to provoke intense balancing Alongside any great power competitions that behavior than is naval hegemony. might arise, or in their absence, there will be A more likely source of conflict between medium powers that aspire to regional the U.S. and a peer competitor would arise if expansion, seek nuclear weapons or provide China and India became embroiled in a them to others, and/or support terrorist struggle for energy security that also involved groups with global reach. This type of con- the medium powers in the Indo-Pacific flict has been ubiquitous in the immediate region. One potential flashpoint for such con- post–Cold War era, and were today’s “unipo- flicts will be the unresolved status of island lar” moment to last forever, it would proba- chains such as the Spratleys, sovereignty over bly be the only type of conflict for which the which may provide access to considerable U.S. military needed to prepare. Iraq, Iran, reserves of offshore oil and/or natural gas. and North Korea all fall into this category. The goal of the United States would be The nature of the wars that the U.S. to play the role of the balancer of last resort might fight against such powers vary widely. in these competitions, and the power that Wars could be fought to prevent or reverse will determine the balance in these compe- territorial expansion by such powers, to stop 17 titions will be seaborne.This will put a pre- the development of nuclear capabilities, or to mium on forces that can independently eliminate support and/or sanctuary for ter- survive in and gain control over contested rorist groups.Wars to prevent or reverse ter- sea and littoral battle spaces against all com- ritorial expansion would most clearly ers, and when necessary, can project power correspond to the major regional contingen- rapidly ashore. The requirements for power cies that dominated DOD force planning projection ashore will stop short of an inde- between the end of the Cold War and 9/11. pendent ability to wrest control of significant Wars to stop a nascent nuclear program land areas from another great power, and will would start with relatively limited strikes be focused instead on the ability to deploy against fixed targets, but would primarily be air forces and, when necessary,ground forces waged to deal with the target country’s retal- rapidly as an equalizer in land conflicts iatory response. For example, the primary between medium powers and larger powers. military challenge of dealing with the cur- Thus, the United States should plan on rent nuclear programs in Iran and North maintaining its global naval hegemony with- Korea is not to mount the attacks against out allied assistance, but it should only plan their fissile material production facilities, but on fighting other great powers on land with to deal with the potential military response the assistance of another medium power. In to those attacks, whether that involves pro- both cases, in the event that a peer competi- tecting shipping and oil industry infrastruc- tor emerges, the battlefields of the longer- ture in the Persian Gulf from Iranian attack, term security environment will be much or Seoul and its environs from North Korea more lethal because the asymmetry in attack. Wars to prevent support for terrorist wealth and technological prowess that favors groups will require successful regime change, involving not only invasion but also Operational Demands on the establishment of a new government, and U.S. Naval Aviation these wars, should the U.S. choose to wage them, will most closely resemble the one the Three operational demands on naval avia- U.S. is engaged in today in Iraq. tion will dominate the future security environment. The first two will be less The Global War on Terror dependent on the nature of the adversary, whereas the third, which is more of a trade- Operation Enduring Freedom sought not off than a demand, will depend heavily on only to attack Al Qaeda, but also to eliminate the nature of the opponent.The first is that the regime that provided it a base in U.S. air forces will increasingly need to Afghanistan and to prevent Afghanistan from deploy and sustain themselves from the sea, being used for that purpose again. As such, rather than from local bases on land. This Enduring Freedom probably represents the demand derives not only from the changed high end of the kind of wars that might be nature of alliance relationships described fought against Al Qaeda or groups like it. above, but also from the revolution in vul- This has led some to note the paradox that nerability to fixed targets that is being caused the war on terror makes the U.S. as con- by GPS. U.S. air forces are already exploiting cerned about weak, failed states, whose very this revolution to “solve” the fixed target weakness creates a threat because it makes problem, but its full consequences will only 18 them candidates for use as a terrorist base, as arrive when opposing forces start to solve it has historically been concerned with states the fixed target problem as well, which they with rising power. inevitably will. Once this process starts, the Whether the war on terror includes key to successful projection of air power will another war like Enduring Freedom, it will be to avoid dependence on fixed bases near almost certainly include operations like the opponent, and instead to deploy and those being conducted today in Djibouti, operate from a secure, mobile sea base. where air, ground, and naval forces operat- The second new demand will be that U.S. ing from an austere base conduct small air forces adapt to the needs of U.S. ground scale, often covert anti-terror operations forces on future battlefields. On those battle- within the region broadly defined by the fields, U.S. ground forces will deploy with Horn of Africa. smaller, distributed force packages that, operat- Another military model for the future ing independently from each other, will use war on terror is represented by the high speed and a flexible scheme of maneuver Proliferation Security Initiative (PSI), which to quickly reach and threaten key objectives. In is a grouping of states willing in advance to so doing, they will advance on external lines, allow their commercial ships to be boarded both exposing their flanks and leaving pockets by other parties to the agreement in case of opposing forces in their rear. U.S. air forces there are suspicions of the transfer of illicit, will have the responsibility of protecting the WMD-related cargos. The PSI is a specific flanks and rear areas of these advancing forces example of a much more general trend, from efforts by enemy ground forces to con- which is that homeland defense in an age of centrate and maneuver in response. terror is a question of maritime security as To accomplish this task, U.S. air forces much as any other factor. will need to be in many different places at the same time, deploying networks of sen- Political Constraints on Access to Bases sors and weapons able to quickly find, iden- Ashore. The political constraints on access tify, track, locate, attack, and assess the to foreign bases affect land and sea-based damage of attacks against mobile targets forces differently.The main difference is not when they emerge.To do this,U.S. air forces that one mode needs overseas bases while will need to supplement today’s model of the other does not, but that land bases launch one large, centrally managed, theater wide weapons while naval bases do not.This dis- network with a model that supports many tinction makes naval bases less threatening to distributed, self-contained networks, each the host nation, not just because it makes able to complete the kill chain autonomous- those bases less of a target, though it may ly within its area of operation. In some low certainly have that effect as well, but because intensity cases, such networks will form it separates the host nation politically from around Expeditionary Strike Groups operat- the actions taken by the U.S. naval forces that ing alone, but in any case where there are use those bases. military threats the sea base will be formed This is a function of the range and around an Expeditionary Strike Force that endurance of naval platforms, which go to sea includes a Carrier Strike Group or Groups. for months at a time, and often operate liter- ally around the world from their bases. The Shift in Emphasis From Certainly, when ships go to sea, they are sup- Local Land Bases to Sea Bases ported by an extensive train of supporting vessels, which replenish supplies of fuel oil, 19 Both political and technological trends limit dry cargo, and, in the midst of a conflict, the military’s access to local bases in regions ammunition. But this umbilical connecting where it will most likely need to project deployed navy combatants to the shore is power. Formal alliances dating from the largely indistinguishable from normal com- Cold War, and the assured access to regional mercial activity,and is in fact often conducted bases that they provided, have declined in by civilian-crewed ships that are essentially relative importance compared to more indistinguishable from their purely commer- informal coalitions formed after a conflict cial counterparts.Thus, for example, when the has already begun. In these coalitions, U.S. U.S. Navy first began regular Indian Ocean forces must generally negotiate access to battle group deployments in the late 1970s regional bases on the fly, and the access that after the fall of the Shah, its oiler and stores results is therefore less predictable in advance ships were able to obtain needed supplies of a conflict than in the past. from a variety of countries along the Indian At the same time, technological trends are Ocean littoral, none of which were willing to making fixed targets more and more vulner- provide any level of base access ashore to able to attack. In particular, when potential land-based American forces. opponents follow the United States in mar- This distinction is reflected in actual legal rying precision guidance technologies to arrangements. For example, everywhere the cruise and ballistic missiles they will be able United States has access to overseas bases for to hold fixed bases within a radius of up to a land-based forces it has an accompanying set 1000 miles at risk of conventional attack by of agreements with the host nation about cruise and ballistic missiles against which how those forces will or will not be used. defense is extremely difficult. Thus, in a recent example, after the Taiwan straits crisis of 1997, the United States appar- to do so, and other cases where only support ently sought to negotiate with Japan over forces such as tankers and airlifters will be future guarantees that bases on its territory allowed to transit. Such access to enroute which were not available in 1997, would be bases is necessary to any major deployment in the future under similar circumstances. No of land-based forces, both because Air such negotiations were necessary regarding Mobility Command airlifters must stage the use of Yokosuka and other U.S. Navy through them, and because air-refueling facilities in Japan, even though the primary tankers must operate from them in order to U.S. military response to the 1997 crisis was refuel deploying aircraft.The same constraint naval, and involved forces homeported in applies to global bomber operations Japan. Likewise, land-based forces have expe- launched from the continental U.S., which rienced significant constraints on the use of are utterly dependent on access to enroute bases in the Persian Gulf region during bases on foreign territory for use by KC- Operations Enduring and Iraqi Freedom, 135s and KC-10s. while sea-based forces have enjoyed unlimit- In addition to gradations in the scope of ed access to naval facilities in the same region. access granted U.S. forces, are gradations in Certainly, this asymmetry in favor of sea the timing with which that access is grant- basing does not come without its costs, and ed. As noted in the first section, it took the sea-based forces may be less cost effective Saudis four days after the Iraqis invaded than analogous land-based forces in those Kuwait to decide that a massive deployment 20 cases where the latter have assured access to of American forces would be in their securi- local, prepared bases in advance of a conflict. ty interest.The speed of the deployment that But as has become eminently clear, this level followed was inestimably aided by the mas- of access will be much less common in the sive pre-positioning of U.S. equipment that future security environment than it was dur- the Saudis had agreed to during the Cold ing the Cold War. War.Thus, a country that already had a major Access for land-based forces can be con- military relationship with the United States, strained in both time and scope. For exam- and which had allowed extensive pre-posi- ple, a country might deny American strike tioned stocks of equipment to be deployed aircraft based there permission to bomb a on its territory in anticipation of a scenario neighbor, but allow aircraft flying supporting like the one it faced in August 1990,still took missions to operate, as has been routine in days to decide how to respond. A country the Persian Gulf region since Desert Storm. with a more tenuous relationship with the Similarly, a country that had allowed the United States, or greater concerns about the United States to pre-position war material projected military operation, might refuse to support rapid deployment of land-based such access, as Turkey did at the outset of forces in a crisis will be likely to support Iraqi Freedom. Finally, access once granted such a deployment only under a particular can also be revoked, as happened abruptly in set of circumstances, against a particular the Fall of 2005 in Uzbekistan. opponent. Also, a country might or might Operations Enduring and Iraqi Freedom not allow a U.S. force to stage through its have provided myriad examples of these var- territory or its air space on the way to ious gradations of access in both time and another country’s bases, and again, there will scope for land-based forces. The central be cases where a country will allow all forces points about this experience are two: the access eventually gained has over time (TBMs) and cruise missiles. Cruise missiles become extensive, but the process that pro- will likely be chosen if an opponent wishes duced this access began after the need for to extend his reach beyond about 600 km.vii the access emerged, was protracted, and the Such cruise missiles might actually have more results were utterly unpredictable from the in common with small aircraft than with cur- vantage point of September 10, 2001. rent cruise missiles like Tomahawk, and might derive their survivability less from high Military Constraints on Access to Bases speed and low radar cross section than from Ashore. The technical trends effecting the their ability to blend in with a noisy back- military security of overseas bases provide a ground and deny an opponent positive iden- case where the demands of the near and far tification.viii This discussion will focus on term security environments appear to rein- TBMs because they are already ubiquitous. force each other, even though the source of Before discussing the impact of GPS/ this similarity is different. This is because INS, it is important to establish what is fixed bases within a radius of 500 to 1000 already true about existing mobile TBM miles of an opponent are likely to become capabilities. TBM defenses have already increasingly vulnerable in the near to mid proven to be at the edge of the scientific- term to conventional attack by GPS/INS- technical capabilities of the United States, guided ballistic and cruise missiles. Over the and even assuming effective TBM defenses longer term, this vulnerability to over the in the future, they will likely be on the los- horizon attack will extend to large ships at ing end of the cost-exchange ratio between 21 sea,but in the near to mid term,such ships are the attacker and the defender. Directed ener- likely to be more survivable than fixed land gy weapons may change this relationship in bases as long as they stand off over the hori- the distant future, but even directed energy zon from an opponent. Satellites, and espe- weapons will be most effective against anti- cially those in low orbits, will also become ship missiles whose warheads must have ter- vulnerable in this time frame. Least likely to minal seekers, because it is more difficult to become vulnerable out through the far term, harden the latter against a laser or high some 30 or more years from now, are under- power microwave than it is to harden an sea platforms. Fast, quiet nuclear submarines INS/GPS-guided warhead used in attacks will remain the least vulnerable of all basing against fixed targets.ix Heretofore, the TBM modes because antisubmarine warfare (ASW) threat has been leavened by the fact that they is least affected by the technical trends that have been very inaccurate.Armed with con- will potentially transform other warfare areas. ventional warheads, their military effects Thus, ASW against modern nuclear sub- have been both low and unpredictable, and marines will remain both extremely demand- armed with nuclear, chemical, or biological ing technically, very expensive, and still a warheads, their use would bring the vastly largely fruitless endeavor. superior American deterrent into play. The trends in the vulnerability of fixed GPS/INS will lead to a quantum leap in bases within a theater will be driven in par- conventional TBM capabilities because it ticular by the marriage of cheap, widely will give them the accuracy needed to attack available GPS/INS guidance technology and soft, fixed military targets with conventional conventional sub-munition payloads with submunition payloads. This is a capability existing, mobile, tactical ballistic missiles that has already been deployed by the U.S. in the form of the U.S. Army’s Tactical Missile AWACS, JSTARS, Rivet Joint, KC-135 and System (ATACMS). Single stage TBMs like KC-10 tankers, and outsize airlifters like the the Chinese M series already provide ranges C-5 and the C-17.x For all these reasons, it of 300-600 km (185-375 miles), payloads of is likely at some point in the mid to long 500 kg (1100 lbs), and conservatively esti- term future that large scale, expeditionary mated accuracies of 100-200 meters (330- deployments of tactical combat aircraft and 660 feet). A 500 kg payload of simple supporting assets will become limited by the submunitions like the M-77 grenade can need to avoid bases within 1000 miles of an destroy soft targets over a circular area of two opponent’s territory. million square feet centered at their point of This constraint will, at a minimum, release. Even with the relatively low accura- reduce by half or more the sortie rate of a cies assumed above, TBMs like this would given size force of tactical aircraft, and wreak havoc on airfields and ports within increase the cost in terms of additional their range. For the purpose of this discus- tanker support and bases for those tankers sion, I will focus on airfield vulnerabilities, necessary to give that force the range to and in particular on those vulnerabilities attack a given set of targets. Perhaps more most relevant to the mid to far term securi- important, there will be circumstances due ty environment. to the political geography of a particular Airfields within range of opposing TBMs conflict in which the only bases potentially will be inherently vulnerable in the expedi- available will be within range of an oppo- 22 tionary environments typical of likely future nent’s missile force. This will lead to cases air operations for four reasons. First, simply where land-based tactical aircraft will be building the hardened shelters to protect five denied access to a given theater altogether, 72 aircraft wings of tactical fighters is a or at least until the threat to their bases has major, multi-billion dollar investment that been suppressed or eliminated by other few potential allies are likely to make on forces. their own. Second, in a world where the location of future conflicts is less predictable The Special Case of Bombers and than it was during the Cold War, the U.S. Overseas Bases. Land-based bombers use will not be able to invest in hardening air- their much greater range than land-based fields in all the potential areas where it may tacair to reduce the number and/or the be called on to fight. Third, even in cases political salience of the overseas bases they where the United States did make this use, and to increase the standoff range of investment during the Cold War, as in Saudi those bases from the opponent. Politically, Arabia, it still proved too expensive to pro- bombers can reduce their vulnerability to vide shelter to the thousands of U.S. person- denied access simply by increasing the prob- nel which must live and work on the base; ability that an amenable ally can be found hence the enormous tent cities which were within range of the opponent.They can also erected on base, which would remain a reduce their vulnerability to being denied lucrative target even at the hardest base. access by taking advantage of the fact that a Finally, it is simply impossible to provide country is more likely to allow tankers rather hardened shelters for the various large, high than combat aircraft to operate from its bases. value support aircraft which are integral to Taken to its extreme, this latter tactic can any expeditionary air operation, such as involve 30-40 hour round trip missions for the bomber and its crew between the United high tempo of operations, their appar- States and a target half way around the world. ent tactical vulnerability was dominat- In these operations, the bomber never uses a ed by their operational advantage since foreign base, but the vast array of tankers that the defender’s intercepting and block- must pre-deployed along its route must do so ing actions would always be one step intensively.Thus, it is almost never the case behind…The whole operation obvi- that long range bombers eliminate all depen- ously rests on the ceaseless mainte- dence on access to foreign bases. What they nance of momentum. Organizationally, do in almost all cases is lessen that depen- this implies a very restricted deploy- dence below the political threshold that can ment of heavier/slower artillery, the lead to access denial. need to keep the supply tail light and Added range is not a free good, which is fast moving will restrict the amount why bombers are much larger and much that can be deployed.” xi more expensive than tactical fighters, and tend to be slower. Also, though their size This description of the German Army’s gives them larger payloads, the added range invasion of France in the Spring of 1940 over which they carry those payloads leads applies almost verbatim to the U.S. Army to reduced sortie rates. Finally, in contested and Marine Corps’ initial operations against air space, bombers cannot defend themselves Iraq in Operation Iraqi Freedom. These against opposing air defenses, which pre- operations will likely serve as a future cludes independent operations by B-52s and model for expeditionary ground force 23 B-1s, and precludes daylight operations by operations. B-2s. These tradeoffs between bombers and In such operations, ground forces will land-based tacair will become more impor- likely strike from several locations at the same tant when military vulnerabilities at overseas time, operating from expeditionary bases on bases are added to the political vulnerabili- external lines surrounding the opponent. ties that already exist. Assuming that there Because of the expeditionary environment, will be limits on the range of these threats and because of the need to maximize the for the foreseeable future, they will improve speed and freedom of maneuver of the the relative advantages of long range aircraft invading force, the size and firepower of the compared to land-based tacair, because bases invading force will frequently not be suffi- outside that range will not need to be cient to win a straight attrition battle with defended and/or hardened. opposing forces. Rather, that force will seek to use speed and maneuver to confuse and Distributed Air to Support paralyze the opponent’s command system, Distributed Ground Forces and to quickly penetrate and descend on the objective from several directions. “…the long thin columns of vehicles Air forces must play a central role in such penetrating through hostile territory operations for two reasons. First, when the were very weak, seemingly highly vul- desired shock effect depends so directly on nerable to attacks on their flanks. the maintenance of momentum, and when Tactically, the columns were of course ground forces must be kept light to create that all flank and no “front.” …(But) so momentum, air support becomes a key source long as the invasion columns kept up a of fires enabling either the rapid elimination of obstacles to the ground force’s advance, or ability, given its’ role in the combined arms their avoidance and later reduction. battle. This is one of the main reasons why Second, such operations absolutely naval aviation is pursuing the cost-effective, depend for their success on the creation of all aspect stealth that F-35C will provide. It chaos and confusion among opposing forces. will enable distributed operations from the In cases when the opponent maintains its first day of any conflict without the prior cohesion at the operational level, as for need for a large defense suppression cam- example did the Allied forces deployed in paign, or the continuing need for dedicated the Ardennes during the Winter of 1944, all defense suppression escorts. of the potential tactical vulnerabilities Distributed operations of this type will described above become real, and the pene- likely dominate the future regardless of the trating columns of the attacker are cut off opponent because they are a potential solu- from their supplies and attacked by opposing tion to problems that occur at both the low forces able to concentrate and maneuver and high ends of the conflict spectrum. At against their weak, exposed flanks.A major if the low end of the spectrum, distributed not dominant mission of future air forces operations make it possible for the combat- will be to detect and destroy such concen- ant commander to deploy a smaller, lighter, trations down to the company level before more sustainable force for the initial opera- they can strike. This requirement is one of tion to repel or assault an opponent’s forces the main drivers behind the need for air in what will often be an austere environ- 24 forces to develop mobile target kill capabili- ment against lesser powers. At the high end ties against opposing ground forces. of the spectrum, it is possible if not likely The specific requirements for such a that distributed operations will prove a mobile target kill capability will be discussed necessity, both to reduce the ground forces’ below, but the main requirement is for air dependence on vulnerable fixed bases and forces capable of being in many places at once, staging areas that can be attacked by the to match the distributed nature of the ground opponent, and to avoid the need for break- battlefield. Distributed air forces assure that through battles against that opponent’s forces targets can be struck quickly when the need in order to envelop and destroy them, perfor such strikes arises. In this respect, the haps via the means of multiple, simultaneous mobile target problem will create demands for vertical envelopments. a very different force than will the fixed target problem. For example, in the latter case, the Concerns About Casualties and lack of time urgency and the desire for effi- Collateral Damage ciency may call for large platforms with large weapon payloads that can attack their targets America’s supposed aversion to casualties in at leisure. Such a force would be inappropriate post Cold War conflicts has been much dis- for the mobile target problem because at any cussed. Fear of casualties often measured in one time, it would only be within minutes of the thousands or even tens of thousands striking one part of a distributed battlefield. dominated the debate over whether to In addition, in cases where the opponent launch a ground war in Desert Storm. In the has significant air defenses, the demand for a event, casualties during Desert Storm were distributed air force must be met from the orders of magnitude lower than expected, very outset of the conflict with absolute reli- leaving the question of America’s tolerance for casualties open for debate.xii Then the strength of the United States’ position in the events of early October 1993 in Mogadishu, world, rather than the weakness of its leaders Somalia seemed to resolve the debate.xiii or its people.The U.S.’s basic security means The death of a small number of Rangers and that it rarely if ever has to fight wars of Delta Force troopers abruptly led the United necessity against formidable opponents, and States to abandon that operation. A growing the general weakness of the enemies it does consensus developed that the United States fight means that U.S. forces are rarely driven could be stopped in its tracks with the deaths by military necessity to make attacks against of a few of its soldiers, leading some to ques- targets where there is any but the smallest tion the viability of its enormous but seem- chance of collateral damage. ingly unusable military power. On the first point, the United States is the The later experience in Kosovo certain- most secure country the world has ever seen: ly did not provide evidence that the United States was not casualty averse, and it also “..(which) leads to something of a para- brought to the fore the related question of dox: Although solving many global rules of engagement and whether its fears problems requires active U.S. involve- of causing collateral damage to civilians and ment, Americans do not see them as civilian infrastructure had come to ham- vital to their own interests and they are string its operations to the point of impo- unwilling to expend much effort tence. For example, NATO air crews were addressing them… Americans would ordered to remain above 15-20,000 feet like to coerce others to do what they 25 throughout the entire conflict because it want, but they aren’t willing to risk was only at that altitude that they remained much blood or treasure to make sure immune from Serbian air defenses, and, of they do.”xiv course, ground forces were foresworn from the outset. This restriction also reduced In this view,America’s aversion to casual- NATO’s ability to distinguish between ties, and the degree to which political lead- Serbian forces on the ground, Kosovar ers will constrain how the military fights in fighters, and fleeing refugees, making it all order to reduce its exposure to casualties will but impossible to stop or limit the ethnic depend on the stakes the United States has cleansing being conducted by Serbian army in the conflict. Because of the great over- and police units in Kosovo, driving NATO hang of American power in today’s security political and military leaders to adopt a environment, and because of its basic securi- gradual strategic bombing campaign ty,few if any conflicts are likely to engage its designed to coerce Serbian compliance vital interests, and many conflicts, like without causing excessive damage to the Kosovo, the first Gulf War, and even the cur- civilian infrastructure, which took months rent war in Iraq, will be viewed by many to succeed. Americans as wars of choice. Using the same As of this writing, Iraqi Freedom has not logic, concerns regarding attacks that might provided unambiguous evidence on this ques- cause collateral damage grow steep when it tion, but it is clear that for those who do is difficult, against a very weak opponent, to oppose the war, U.S. casualties are a major argue that military necessity allows no alter- cause of that opposition.The explanation for native to launching those attacks. this aversion has more to do with the This basic structural paradox sets the bar extremely high for the U.S. military, because the prospect that fleeting targets could be it must win while keeping its losses and col- struck before they disappeared again, and lateral damage extremely low by historical reducing the overall operational risks associ- standards. Certainly, the pressures in this ated with distributed operations. On the regard will vary somewhat, depending on other hand, when political and military lead- whether a conflict is a major contingency ers have to weigh the political costs of either like Iraqi Freedom, or instead, a humanitari- casualties or collateral damage in limited an intervention in Latin America or Central conflicts, they will remain reluctant to allow Africa.Yet in the absence of major war with such decentralization, and concepts of oper- a great power, there is little prospect that the ation will tend toward centralized control U.S. military will see this bar lowered. and execution. The main military consequences of this The perceived cost of casualties and col- reality will be a growing demand for lateral damage would certainly change in weapons which can stand off at a distance wars of necessity when military necessity from enemy defenses and avoid direct fire demanded it. But it is important to note that engagements with their targets at short concepts of operation bred in today’s securi- ranges, but also growing demands for very ty environment will have a tendency to precise identification of targets before they “reify” themselves in the doctrine and force are attacked and very precise results when structure of tomorrow’s forces. This issue is attacks are approved. In many cases, such as in of particular importance to air forces, where 26 attacks from the air against high profile, fixed both the desire and the ability to centralize targets on the ground, precision weapons execution is felt most strongly by military have or soon will solve these problems. In leaders prosecuting wars of choice against other cases, such as in attacks from the air weak opponents, but where the conse- against military vehicles or convoys outside quences of building centralization into of contact with friendly ground forces, the future doctrine and systems could be devas- problem of combining precise identification tating in the event U.S. forces faced more and weapon effects with essential immunity formidable opponents. from attack is far from solved. In still other cases, such as in today’s urban counter-insur- Technology Trends in the New gency operations in Iraq, it is only possible to Security Environment imagine solutions to this problem through the deep integration of air and ground forces Longer term trends in technology are more down to the smallest units. difficult to predict, but some can be identi- Another consequence of this problem is a fied with more or less confidence. As in the tradeoff between concepts of operation previous discussion of operational demands, which devolve the maximum degree of some trends in technology are general and authority to execute operations to the apply across all or many mission areas, while engaged units, and those that concentrate others apply most strongly to a particular decision making and execution authority at mission area. The following discussion will central operations centers. In an ideal world, emphasize those trends that are likely to distributed operations would lead to radical- apply across all or most mission areas. ly decentralized execution authority,thereby The conventional wisdom in the U.S. speeding up the decision cycle, maximizing defense department regarding the future of military technology appears to contain at least also easier to shoot down then satellites and five assumptions or desires: that space-based must generally standoff some distance from sensors will play a larger role in future opera- hostile air space until opposing defenses are tions; that sensors, however based, will increas- suppressed or destroyed. ingly be linked to form networks, rather than By contrast, the limits of spaceborne sen- used independently; that unmanned vehicles sors are more subtle and generally require a in the air, on the ground, and on and below technical understanding that is largely absent the surface of the sea will increasingly from most public debates. For example, air- takeover missions now assigned to manned borne sensors can dwell in a given area for platforms; that more and more battlefield an extended period of time, with its sensor information processing, decision making and performance limited only by line-of-sight control will be centralized in rear area opera- constraints. Satellites, on the other hand, face tions centers; and that the bandwidth to a tradeoff between low orbits, where sensor enable networks, operate unmanned vehicles, performance is maximized but dwell time in and support rear area operations centers will any one area is measured only in minutes, be available. Certainly, all of these trends are and much higher synchronous orbits, where real and all are likely to continue, but at the dwell time is maximized but where many same time, each can also be taken too far. sensor phenomenologies are ineffective because of the great distance to the earth’s Space-Based Sensors surface. For example, radar and optical imaging sensors cannot be deployed in synchro- 27 There is a long history of the tactical ex- nous orbit. ploitation by the defense department of so- Therefore, to achieve the dwell time nec- called national capabilities, or space-based essary for surveillance as opposed to recon- sensors. These efforts exploited assets that naissance, radar and optical imaging sensors were already in orbit that were designed, in low earth orbit must be deployed in con- procured, and operated by the intelligence stellations of 20-40 satellites in order to community.Today, there is much discussion ensure that one is over the area of interest at of space-based systems that would be devel- any time. By contrast, a single airborne sen- oped and operated jointly by DOD and the sor platform can provide continuous surveil- intelligence community, and which would lance of a given area for many hours, and therefore be designed from the outset with three or four can provide 24 hour surveil- DOD’s as well as the intelligence communi- lance indefinitely. ty’s needs in mind. Airborne sensor platforms can also deploy It is easy to show what the inherent limits larger antennas with more powerful and con- of airborne sensor platforms are compared to tinuous power supplies. This is particularly spaceborne sensor platforms. Airborne sen- relevant in the case of MTI radars, whose sors can only see out to the horizon, out to performance is very sensitive to power and perhaps 200 miles at the most. Spaceborne aperture.Airborne sensor platforms also have sensors looking down at the earth from low significant advantages when used as SIGINT earth orbit can see a patch of ground at least platforms against highly directional signals twice that area, and from geosynchronous such as those generated by air defense orbit, satellites can “see” almost an entire engagement radars, whose main beams prop- hemisphere. Airborne sensor platforms are agate horizontally rather than vertically. Because of these various tradeoffs, space trast, the antennas used in a TDOA/FDOA and airborne sensor platforms should com- network can be extremely small and cheap plement each other, but as in many mission because the angular resolution of the nodes in areas, it is difficult for many casual observers the network become irrelevant to its perfor- not to see two different platforms deploying mance. In this extreme case, a network com- the same types of sensors as duplicative.Add prised of several very simple nodes not only to this the fact that a satellite remains a vast- outperforms a single, very sophisticated plat- ly more expensive method of deploying a form, but is also much cheaper. sensor than an airborne platform and it is But many ignore the assumptions hidden in easy to see how a push to transform space this comparison. First and most obviously,such reconnaissance into space surveillance could networks fail deadly. That is,they require a cer- have unintended and undesirable conse- tain number of nodes to function, and quences for the Department of Defense if it deprived of even one node they fail complete- comes at the expense of the ability to fund ly. There is no graceful degradation in a airborne surveillance platforms. TDOA/FDOA ELINT network if its individual sensor nodes are not also designed to oper- Sensor Networks ate alone. Second, in the case where network designers anticipate this vulnerability, they can Whether deployed in space, in the air, on the seek to deploy redundant sensor nodes to ground, or under the sea, sensor performance compensate for losses or malfunctions, but in 28 can often be improved dramatically when the this case they must also ensure that a high output of multiple sensors is compared and degree of self-organization and self-healing is fuzed. For example, even the most advanced built into the network. Otherwise, the addi- RF antennas have inherent limits in their res- tional, redundant sensor nodes can become a olution which, at longer ranges, produce errors source of error rather than insurance. Finally,in in target location measured in 100s if not denied or contested environments, it is often 1000s of feet in azimuth for MTI radars and difficult to deploy and operate any sensors at ELINT receivers. These errors can be elimi- all, never mind a redundant network. nated or dramatically reduced if several sensors An alternative approach to network are deployed within line-of-sight of the target design would look at networks as an oppor- and of each other and their output data-linked tunity to greatly expand the potential capa- and processed. Two or three networked MTI bilities of individual sensor platforms that radars using trilateration can precisely locate can function autonomously if necessary. and track a moving target, and two or three Certainly, in the near to mid term, there is networked ELINT receivers using some com- the need for considerable experimentation bination of TDOA and FDOA processing can to determine both the strengths and weak- precisely locate a hostile radar. nesses of networking, and a strategy that led Furthermore, in many cases, networking to the deployment and use of networks that can enable a significant reduction in the cost failed safe rather than deadly would have real of individual sensors. For example, the best benefits.There is also considerable promise in ELINT antennas with angular resolutions the use of networks where the nodes are so measured in single degrees or even fractions of cheap as to be truly expendable. These will a degree require large platforms like the RC- usually be networks of passive sensors and 135, and are therefore very expensive. By con- will therefore also provide the potential for covert surveillance. Such networks would space without collision, and it also allows provide an ideal venue for experimentation aircraft to respond immediately to a vari- with self-organizing and self-healing systems. ety of hostile threats, either to avoid them or attack them. Air crews accomplish this Unmanned Aerial Platforms function by constantly monitoring a variety of sensors and cues, including predom- Taking the aircrew out of an airborne plat- inantly what they collect themselves form can clearly solve some important mili- visually on a continuous basis.As with tar- tary problems. High endurance, high altitude get recognition, it is difficult to imagine UAVs like Global Hawk have amply demon- automating this function. strated their worth as sensor platforms, and In short, providing target recognition and both the altitude and endurance of their oper- situational awareness capabilities to UCAVs ation are simultaneously the source of their will likely still require crews, but those crews relative value and the result of taking the air- will be physically separated from the multi- crews out of the platforms and putting them tude of sensors that provide that capability. on the ground. By the same token, a cruise The bridge linking the crews to their sensors missile like Tomahawk that can fly up to 1000 will be data links, some of the constraints of miles into contested air space eliminates the which will be discussed below. The one operational tradeoff between deep penetration unambiguous advantage of separating air attacks by platforms like the B-2 and the need crews from their platforms is the increase in to keep air crews within range of helicopter- the latter’s range and endurance that becomes 29 based combat search and rescue (CSAR) assets possible. For example, in the case of carrier whose range is limited to 2-300 miles. aviation, whatever payloads are deployed on The next step in unmanned aerial plat- carrier-based UCAVs, the ability to deploy forms is assumed by many to be some sort those payloads on platforms with a 1500 mile of unmanned combat air vehicle (UCAV) radius and 12 hour endurance will be the fac- which would deploy both sensors and tor that drives their adoption. weapons into contested air space and return to be reused again. In many eyes, Centralized Air Operations UCAVs are viewed as successors to Centers manned strike fighters. This implies many things, among them that UCAVs can be Since the first Gulf War, combined air opera- provided the target recognition and situa- tions centers (CAOCs) and other rear area tional awareness capabilities that air crews processing facilities have played an increasing provide strike fighters. role in air operations. The use of the word For example, target recognition often combined implies correctly what the function involves the generation and interpretation of these centers has been – to combine a series of high resolution images. At some point of normally separate streams of intelligence, in the future it may become possible to surveillance, and reconnaissance assets into a automate that process, but today and for a fuzed picture of the battlefield to support number of years target recognition will decision making by high level leaders. A require people to interpret the images. CAOC can also be described with equal Situational awareness allows many air- accuracy as a means of centralizing decision borne vehicles to operate in the same air making authority on the battlefield. Specifically, CAOCs are a place to fuze networking if necessary,in which operations the output of many independent sensors, directly supported by the CAOC were a whether spaceborne, airborne, on the sur- very small albeit important subset of the face or under the sea. When it is necessary whole, and in which the forces deployed by or desirable to create networks of sensors, the opponents were vastly inferior, particu- CAOCs are often a place to do the unique larly in qualitative terms. processing that gives those networks their power. And certainly, if UCAVs are Secure High Data Rate deployed in large numbers, CAOCs or rear Communications area locations like them will be one place to put the ground crews that will give those In a future where it is assumed that many assets their target recognition and situation- tactically relevant sensors are deployed in al awareness capabilities. space as well as in the air and on the surface, Such centralization has two major conse- that sensors are often formed into networks, quences, one that is obvious and that will be that sensors and weapons will deploy into discussed in the next section. The other contested air space on unmanned platforms, consequence is more subtle. Operations by and that ISR information is combined and even modest-sized forces on cluttered bat- weapon release authority centralized in rear tlefields generate the need for thousands of area operations centers, one capability above tactical decisions a second, most of which all others will be required—the ability to 30 are obviously made on the spot in real time move vast amounts of data between many by small units and individuals who then also 100s if not 1000s of mobile platforms, reli- become the means of executing those deci- ably and over great distances.The solution so sions. If one seeks to take any significant far to this emerging issue has been to lease percentage of this activity and physically bandwidth on commercial satellites. separate the means of decision from the But if future opponents have even mod- means of execution, and if one wishes to estly better electronic warfare capabilities than preserve if not accelerate speed and respon- todays’ opponents, never mind if a true peer siveness, then both the number of indepen- competitor should emerge, than those high dent, rear area decision makers and the data rate communication links will have to be bandwidth connecting them to their means secured in the face of efforts to jam them. of execution become fundamental determi- Today, in the entire Department of Defense, nants of the possible pace and scope of mil- there is not a single communication system itary operations. that comes close to achieving this objective. Of course, this is ironic because CAOCs The problem is that data rate and jam have for the last decade increasingly been the resistance directly compete for the same scene of successful efforts to speed up deci- bandwidth. For example, UAVs like Global sion making and execution, but this progress Hawk and Predator often use commercial has occurred during a phase when the main satellite communication systems operating at obstacle to fuzing or networking informa- Ku band (10-15 GHz) when they need to tion was technical rather than bureaucratic. relay their sensor outputs over the horizon. It also has occurred during conflicts in These satellites are designed to maximize which U.S. forces were still designed and data rate and can support links with trained to operate without ISR fusion and throughputs of 10s of MBs/sec. but are thor- oughly vulnerable to simple noise jamming potential to address the data rate/security from anywhere within their uplink antenna’s tradeoff in at least three ways. First, the footprint, which for a geosynchronous orbit ground footprint of an airborne receive is always large. By contrast, Milstar, a DOD antenna is much smaller than for a satellite satellite system which operates at even high- antenna, which means that the area from er Ka band frequencies (and therefore high- which an opposing jammer could introduce a er bandwidth), is optimized toward jam spurious signal into the antenna is also great- resistance and will only support data rates ly reduced, making it easier either to use array measured in 10s of KBs/sec; i.e. several gain to suppress the spurious signal or to take orders of magnitude less. Hybrid waveforms offensive action against the jammer itself. at Ka band used on Milstar II that seek a Second, line-of-sight links lose much less of compromise between jam resistance and data their signal strength to propagation losses and rate can support data rates of roughly 1.5 data rates are therefore inherently higher, pro- MBs/sec, or the equivalent of a T-1 line. At viding the waveform designer with a higher lower frequencies, such as the ubiquitous base to trade from in seeking to build in some UHF SatCom systems which are most use- jam resistance. And finally, because airborne ful to tactical forces because they do not platforms are much cheaper than satellites, it require expensive terminals and highly is possible to create networks with many directional antennas, such as those used by more nodes, all within line-of-sight of each Milstar, there is much less bandwidth avail- other but arrayed along different azimuths able, and therefore both data rates and jam from any one jammer. Azimuth diversity 31 resistance are inherently low. combined with packet switching could One option for addressing this problem enable an airborne communications network within a specific area of operations is to rely that resembled the terrestrial internet in that more on networks of airborne relay platforms it could experience a loss of the link between that are linked by line-of-sight communica- any two nodes and still allow them to com- tions. Such airborne networks have the municate with each other. If one looks around the world, one can identify those few countries with serious air defenses by the presence of AEW aircraft. At sea, the presence or absence of carrier-borne AEW is even more decisive. Sea Shield Past, Present, and Future

ECAUSE THE OTHER SERVICES are end of the Cold War, but both remain likely to face political constraints on important sources of sea denial leverage for Btheir access ashore early in future con- future opponents. That is because modern, flicts, the Navy will face greater demands on non-nuclear submarines and mines remain its power projection capabilities. But the in some ways the ultimate conventional, Navy will also remain largely if not solely asymmetric threats. They can do damage to responsible for countering opposing access major, high value naval platforms, yet they denial efforts at sea, both to ensure the secu- can only be countered by an effort whose rity of its own base of operations, and to cost greatly exceeds that necessary to gener- enable the safe entry and secure operation of ate the initial threat.Thus, they pose unique joint, follow-on forces. challenges in today’s security environment This section is organized in three parts. It because they remain one of the best ways to discusses the evolution of the demands on cause politically significant losses to the Navy’s access assurance capabilities dur- American or allied ships despite the dramat- ing and since the end of the Cold War; the ic diminution in the overall level of the ASW 33 current status of sensors, weapons, and net- and mine threat compared to the Cold War. works in this mission area; and future oppor- This often makes the case for better ASW tunities for innovation in both technology and mine warfare capabilities both important and doctrine by naval aviation. and difficult to make in today’s budgetary environment. The Cold War Legacy ASW During the Cold War. After World The pillars of today’s and tomorrow’s Sea War II,Soviet submarines based on captured Shield posture were laid during the Cold German designs threatened to render obso- War in the undersea and antiair warfare mis- lete much of the U.S. Navy's ASW posture, sion areas. In these warfare areas, the Navy which had been focused on dealing with faced an opponent whose prime focus was submarines that lost a substantial portion of the denial of access by sea-based power pro- their offensive capabilities when forced to jection forces, and who chose what would submerge. At the same time, the Soviet now be called asymmetric means in the pur- Union, being a continental power, threat- suit of that goal. ened to make the U.S. Navy's victorious submarine force irrelevant, since submarines Undersea Warfare were primarily useful as an anti-surface weapon against merchant shipping, and the Undersea warfare can be divided for our Soviet Union could easily survive without purposes into antisubmarine warfare and merchant shipping. counter-mine warfare. Both warfare areas Out of this challenge grew two initially have experienced dramatic change since the separate innovations which, when brought together, formed one of the cornerstones of weaknesses of each ASW platform. Thus, the U.S. Navy's Cold War ASW posture. submarines went forward into contested The first innovation involved the exploita- waters where other ASW platforms could tion of passive acoustics to detect and track not operate, maritime patrol aircraft used submerged submarines, using the sounds they their speed to prosecute long range contacts generated as a signature. Passive sonars signif- generated by underwater surveillance sys- icantly increased the range at which sub- tems, and surface combatants utilized their merged submarines could be detected endurance to provide a local screen for bat- compared to active sonar, allowing for very tlegroups and convoys. wide area searches by ocean-wide sound sur- The key to success in these relatively veillance systems, which in turn could be uncoordinated operations was maintaining a used to accurately cue ASW platforms to high degree of acoustic superiority over localize and prosecute the submarine contact. Soviet submarines. Ironically, that superiori- The second innovation began with the ty began waning in the 1980s, just as the embrace by the U.S. Navy's submarine and Cold War was ending, in an echo of the end maritime patrol communities of ASW as their of World War II.This ending to what was the primary Cold War missions, using passive third battle of the Atlantic was fortunate, but acoustics as their primary method for search, the Navy will face new ASW challenges not classification, and localization. unlike those it avoided when the Soviet Maritime patrol aircraft offered speed that Union collapsed, albeit on a smaller scale. 34 submarines lacked, making them particularly useful in the initial localization of a contact ASW After the Cold War. The threat to provided by offboard surveillance systems, American acoustic superiority resulting from which could then be handed off to a plat- the first Soviet deployments of the Akula in form with more endurance, such as a nuclear the mid 1980s may recur in today's security submarine. The surface warfare community environment with the increasingly wide pro- remained dependent on active sonar until the liferation of modern non-nuclear sub- late 1970s.Then, in response to the deploy- marines. Deployed relatively close to their ment of more capable Soviet submarine- homes, in or near littoral waters through launched antiship missiles, surface combatants which the United States may need to project also embraced passive acoustics and long power from the sea, and where it is easier for range, shipborne ASW helicopters. a weaker Navy to obtain cueing information By the early 1980s, all of the Navy's plat- against U.S. ships, these submarines pose a form communities were being used success- potentially formidable threat.With a compe- fully in ASW operations against Soviet tent crew and the kind of advanced weapons submarines, and increasingly these opera- that are now widely available in global arms tions demanded a high degree of coordina- markets, a modern non-nuclear submarine tion as Soviet submarines became quieter. deployed in its own backyard might become Earlier in the Cold War, when U.S. acoustic a poor man's Akula. Of even more concern is superiority was still unchallenged, each plat- the fact that modern weapons, such as wake form community's ASW operations had homing torpedoes for example, tend to been relatively independent of each other. reduce the demands on submarine crews, This independence reflected a natural divi- making even less competent crews too dan- sion of labor based on the strengths and gerous to ignore. Modern non-nuclear submarines are ment, but will be very hard to defend both better than those deployed by the against in those cases where the weapon Soviet Union during the Cold War, and homes on the right target. This threat cir- more widely available as defense industries cumvents the traditional ASW approach to that served their home markets during the dealing with very quiet diesel-electrics, i.e. Cold War now use exports to stay alive. One to flood the ocean surface with radar and reason that the submarines are better is use speed to force the submarine to either because many decades of continual invest- run down its battery and expose itself in an ment by countries like Germany and attack run, or stay quiet and defensive. Sweden have finally paid off in the form of There is also a political challenge associ- non-nuclear submarines with both rafted ated with conflicts in which the United diesel propulsion plants that greatly reduce States is fighting over less than all out stakes. their acoustic signature when snorkeling, In such conflicts, there will be a very low and with air independent propulsion (AIP) tolerance for shipping losses, but the pres- systems that make them more like true sub- ence of an opposing submarine force will marines rather than mere submersibles. put great pressure on the Navy if it must These submarines still do not provide any- rapidly project power and protect against thing like the mobility and endurance of a those submarines at the same time. nuclear submarine, but they reduce the indis- Regarding casualties, even in a major cretion rate of a traditional diesel-electric regional contingency, the stakes for the submarine when on a slow speed patrol. Such United States are limited while those of its 35 a submarine, patrolling in a limited area in or opponents are very high indeed.The oppo- near its home waters, would need to expose nent may be willing to run great risks and its snorkeling mast much less frequently than sustain high losses, while the U.S. is less will- do older versions of the Russian Kilo and ing to do so. Faced with the possibility or would be less vulnerable when it did. the reality of losses at sea, the Navy will Such submarines will also be armed need to mount a major effort to eliminate with better weapons and fire control sys- the threat of further losses. In order to be tems. One particularly alarming develop- able to do this while still projecting its own ment is the marriage made possible by the power, the Navy will need to make ASW a end of the Cold War of the air indepen- less protracted and asset-intensive exercise. dent, non-nuclear submarine with the sub- A good analogy is to the great Scud hunt marine-launched antiship missile. Armed of Desert Storm.Thousands of sorties were with Harpoons or Exocets available from diverted over several weeks from the air war several western suppliers, or Russian mis- during Desert Storm to hunt for SCUDs to siles like the Novator 3M-54E, these plat- little or no effect. From an ASW perspective, forms can launch fire and forget missiles this experience is illuminating for both from over a surface ship’s radar horizon operational and political reasons. without the need for the noisy and battery- Operationally, Scud hunting was like draining approach run necessary for a tradi- ASW using traditional methods against a tional, torpedo-armed, diesel-electric boat. very quiet target. A large area needed to be Absent high quality over-the-horizon cue- searched for objects that easily blended into ing, these attacks will be prone to homing the background and only intermittently on the wrong target in a cluttered environ- exposed themselves.Thus radar was used to flood SCUD operating areas, unattended ASW will also be the primary tool for ground sensors were also deployed, and air- protecting merchant fleets if and when craft were used to pounce on potential con- attacks against them are launched by an tacts. This was a protracted, extremely asset opponent seeking to coerce a third country intensive endeavor, characterized by false by attacking it commercial shipping. The alarms, high weapon expenditures, and low capability to assure the protection of its success rates. In short, a SCUD launcher was commercial shipping will probably be the most likely to reveal itself by successfully single most important kind of security guar- launching its weapon, just as sinking ships antee that the United States will be able to are often the only reliable indication that offer medium-sized powers along the Indo- there is a submarine in the neighborhood. Pacific littoral, because it is likely that sub- The political lessons of the SCUD hunt marine-based threats to that shipping will be also apply to ASW.Before the war, the SCUD the primary source of leverage deployed by had rightly been dismissed as a serious mili- any would be hegemon in the region. This tary threat, but once they began landing in argument applies with particular force to Israel, the political imperative to allocate those countries dependent on external scarce resources to at least appear to counter sources of energy that are shipped by sea. this threat rapidly overwhelmed these narrow There is also a doctrinal challenge the military calculations.The same political pres- Navy faces as it attempts to increase its abil- sures would be brought to bear on ASW ity to project power from the sea.The Navy 36 forces facing active enemy submarines, but faces a new operating environment in which unlike the Iraqi Scuds, which were terror it is increasingly relevant and therefore in weapons without much military utility, sub- demand. Unlike in the post WWII era when marines are a serious military threat as well a the Navy was searching for a mission, it has political one. Therefore, it will be important been inundated with new missions in the to avoid delays in containing the ASW threat, post Cold War era, and these new missions and an ensuing delay in the closure of Marine compete with ASW for resources. amphibians or Army sealift ships. This has serious consequences for ASW A delay of several weeks during the halting because, as noted above,ASW is a multi-plat- phase of a major contingency might not be a form mission area performed by multi-mis- war stopper all by itself, but it is important to sion platforms. As the Navy’s strike warfare, understand the consequences for current time anti-air warfare, missile defense, and phased force deployment list (TPFDL) time- amphibious warfare capabilities have grown lines, which assume closure of millions of in importance in the nation’s military strate- square feet of pre-positioned sealift within the gy, the Navy has shifted its focus away from first two weeks of the start of an MRC.This an emphasis on blue water sea control would transform a rapid deployment into a toward power projection and land control in slow one, throw the deployment timelines of the littorals.Yet these missions must be per- all the services askew, and open a window of formed by the same platforms that will per- indeterminate size at the outset of a conflict in form ASW in the littorals - the air, surface, which the enemy can operate unmolested and submarine communities, all supported except by those opposing forces already in the- by the ocean surveillance community. ater, assuming they do not need an open sea This “multi-mission pull” increasingly line of communication to sustain themselves. makes ASW compete with strike warfare and theater air and missile defense for the but during the Cold War its counter mine same resources and training opportunities. posture was determined largely by a small This shift in orientation is occurring at a subset of this threat. First, traditional time when technology increasingly demands amphibious assaults was not considered like- that ASW be a coordinated, “combined ly in a major war with the Soviet Union, and arms” exercise if it is to succeed.All elements though the Navy and the Marine Corps of the Navy’s ASW posture must be main- retained capabilities to clear mines in the tained to succeed in the fight against quiet approaches to a landing beach, the require- submarines, but all three of the Navy’s major ments in this mission area were set at the rel- platform communities also face pressures to atively low level expected in lesser improve the capabilities of their multimis- contingencies. Second, the U.S. Navy’s main sion platforms in other mission areas. operational focus during the Cold War lay in countering the Soviet Navy’s expected Mine Warfare During and After the attempts to contest control of the Atlantic Cold War. Counter-mine warfare in today’s and Pacific sea lines of communications security environment shares much in com- (SLOCs). In this blue water environment, mon with ASW,but is also unique in several mines were a minor factor. Certainly there respects. Like modern non-nuclear sub- were ports at both ends of these SLOCs, and marines operating on battery, mines can not there were also shallow,enclosed seas like the be detected at operationally significant Baltic and Yellow Seas which would have ranges using passive sonar, and they “oper- been contested, but here Allied navies bore 37 ate” in a shallow, cluttered environment in the brunt of the counter-mine burden. The which their small size and ability to remain main exception to this division of labor lay in still while retaining operational effectiveness the need for the U.S. Navy to assure access to all conspire to make detection and classifica- ports in the United States. For this purpose, tion with active sonar extremely difficult. the Navy developed and maintained a dedi- Likewise, in their effects, they also pose the cated, U.S.-based Mine Countermeasure same kind of asymmetric threat in opera- (MCM) force. tions where the U.S. Navy and its allies must Desert Shield illustrated two weaknesses limit ship losses to very low levels. in this posture. First, early arriving naval Like submarine-launched torpedoes, forces lacked the organic MCM capabilities mines attack ships under their waterline needed in the event of an aggressive Iraqi which makes them extremely lethal, but mine laying effort in the shallow waters of unlike submarines, mines lack mobility.Thus the Persian Gulf. In the event, a relatively even more then submarines, mines are only small and incompetent Iraqi mine laying effective when used in confined waters or effort led to two major ship casualties. chokepoints, and most mines also require rel- Second, even after dedicated MCM forces atively shallow water.Thus, mines have always arrived in the Gulf after several months, had particular utility when used to limit pas- these forces could not clear the extensive sage to and from ports, to limit the operation mine defenses the Iraqis had prepared along of ships in shallow coastal waters or straits, and the Kuwaiti coastline with sufficient confi- to frustrate or delay amphibious assaults. dence to enable an amphibious assault. All of these potential uses for mines have This experience highlighted the new been of historic concern for the U.S. Navy, MCM challenges presented by the new security environment. First, CONUS-based, saries can both deploy long range sea sur- dedicated MCM forces can not deploy fast veillance systems and maneuvering reentry enough to support a forward deployed Navy vehicles with effective terminal sensors. that must confidently operate in littoral GPS-guided ballistic and cruise missiles can waters early in a conflict, so those forward already now pose threats to bases ashore. deployed forces must have organic MCM Thus, the Navy will both need to defend capabilities that at least allow them to find, itself at sea against cruise missiles and, per- identify, and evade mines that would other- haps, ballistic missiles, and also project a wise limit its access. Second, a serious min- defense against such weapons ashore. ing effort by a competent adversary using modern mines will demand MCM capabili- Antiship Missile Defense During the ties based on new technology not resident in Cold War. During World War II, the inte- existing MCM forces. grated air defenses contained within Carrier This challenge will be most serious in Task Forces became quite effective against two specific scenarios where mines can Japanese dive bombers and torpedo bombers extract the greatest leverage; in deterring for two reasons. First, they projected the amphibious assaults against prepared coastal defense outward such that many Japanese defenses, and in delaying or interdicting the aircraft never delivered their weapons, and deployment and sustainment of land-based second, their inner or terminal defenses forces by mining the ports of debarkation to greatly reduced the effectiveness of weapons 38 which their sealift must have timely and that were delivered by deterring most unimpeded access. In the second of these Japanese pilots from flying the delivery pro- scenarios, the ASW and MCM challenges files necessary to give the short-ranged and may merge, as the submarine may be the unguided antiship weapons of the day the only mining platform available to a weaker accuracy needed to strike a maneuvering power seeking to operate in an opponent’s ship with reasonable probability. home waters. In both cases, the U.S. Navy’s During the last year of the war, two new challenge is to enable power projection and AAW challenges presented themselves. First, sustainment by joint forces, and to protect the Navy’s Carrier Task Forces switched commercial shipping routes. from pursuing the by then defeated Japanese fleet to supporting amphibious assaults Antiair Warfare beyond the range of land-based, tactical aircraft. This fixed carrier operations in space As with undersea warfare, elements of the and time, making their movements more U.S. Navy’s current antiair warfare (AAW) confined and predictable, and therefore posture can be traced back to its experience making them easier for opposing, land-based in World War II.Today’s antiship cruise mis- air forces to find. Furthermore, this limita- sile threat is the descendant of the Kamikaze tion on the carriers’ ability to use movement threat and has traditionally represented the and deception to frustrate Japanese air primary above-the-waterline access con- attacks lasted for the weeks or months that it straint for naval surface combatants. Non- took to build up land-based aviation ashore. nuclear, land-based ballistic missiles have not Second, it was also at this point that the traditionally posed threats to ships at sea, but Japanese introduced the Kamikaze tactic. could in the future if more advanced adver- The challenge posed by Kamikaze aircraft was that their pilots were no longer endurance and were not yet truly night/all deterred by a Task Force’s terminal defens- weather platforms. Furthermore, antiaircraft es, making the platforms they were piloting guns were almost completely ineffective into very intelligent missiles that were against antiship missiles with jet and later guided all the way to their targets. These rocket motors. aircraft had no better luck than their non- Out of this threat grew several major Kamikaze counterparts penetrating a task innovations which have become keystones force’s outer defenses, but those that did of any modern integrated air defense system. penetrate were much more lethal. Thus, Carrier-based airborne warning and control Carrier Task Forces became easier to find aircraft with powerful radars were developed because they were tethered to the shore for and deployed which greatly extended the an extended period, and their terminal outer ring of a Battle Group’s defenses by defenses were less effective against guided providing much more warning of attack. weapons that could not be deterred from Radar-guided surface-to-air missiles (SAMs) pressing home their attacks. were developed and deployed. SAMs greatly During the Cold War, the evolution of the increased the reach and effectiveness of an antiship missile threat went through three individual ship’s defenses. Ships so equipped phases corresponding to the years when the provided true night/all weather air defense Carrier Battle Group was expected to be a capability, and with a family of missiles of primary nuclear delivery platform against the varying size and range–the so-called 3-Ts: Soviet Union (roughly 1948-1960), the years Terrier,Tartar, and Talos;these ships also con- 39 when Battle Groups were focused on pro- tributed to both the outer and inner defens- jecting power in limited conflicts in the third es of a Battle Group. world (roughly 1960-1975), and the years A less visible but equally important inno- when Battle Groups refocused on operations vation of this period was the development against the Soviet Union, albeit in a primar- and deployment of the Naval Tactical Data ily conventional rather than a nuclear role System (NTDS). NTDS was the first widely- (roughly 1975-1990). used digital data link and it grew out of the During the first phase, the Soviet Navy need to integrate the Battle Group’s air deployed radar-guided missiles in both air defense systems in a period when the speed and submarine-launched versions that were and complexity of AAW operations had designed to defend Soviet territory from exceeded the capacity of voice radio links carrier-based nuclear strikes. Launched from and yeomen with grease pencils writing faster, higher flying, radar-equipped jet air- backwards on glass tracking boards. craft like the Badger, these air-launched mis- Thus began a classic measure/counter- siles posed a day or night, all weather threat measure race between Navy fleet air defense to the carriers which could not be coun- systems and Soviet antiship systems. Soviet tered by traditional air defense systems. ASMs grew faster and developed longer legs, Attacking jet aircraft approached the carrier forcing the Navy to further extend the outer too high and fast for reactive, deck-launched rings of its Battle Groups’ air defenses, and to intercepts to be effective, while the tactic of improve its SAM-based inner rings. It was at having a continuous combat air patrol in the this point that E-2 warning aircraft and F-4 air above the carrier was infeasible using the interceptors armed with radar guided air-to- Navy’s early jet interceptors, which had low air missiles became the mainstay of the Battle Group’s outer ring of air defenses.The need flight. Linked together by real time data to stand off from greater distances forced the links, these assets collectively extended the Soviet Navy to improve its ocean surveil- outer air battle hundreds of miles from the lance and over-the-horizon targeting capa- Battle Group, reestablishing a robust barrier bilities, which in turn led the Navy to place that SNA needed to penetrate before it increasing emphasis on evading, spoofing, or could launch its missiles. destroying those systems. At the same time, the Aegis weapon sys- This race abated somewhat during the tem was deployed during this period. Aegis Vietnam years when the Navy’s Battle vastly expanded the capabilities of the Navy’s Groups were focused on power projection air defense cruisers to deal with antiship mis- operations in Southeast Asia, but renewed siles that leaked through a Battle Group’s with a vengeance during the third phase of outer ring. Its phased array radar could track Cold War AAW operations. The Navy hundreds rather than tens of targets simulta- emerged from the Vietnam years facing a neously, and its target illuminators could Soviet Navy armed with a space-based guide up to 16 SAMs simultaneously, rather ocean surveillance system that used radar than one or two. Furthermore, because and ELINT satellites to find and identify Soviet antiship missiles flew high altitude, U.S. ships, and provide over-the-horizon tar- arcing profiles in order to extend their range, geting information to long range Soviet Aegis could see them at great distances, and Naval Aviation (SNA) and nuclear powered because of the speed with which Aegis could 40 cruise missile submarines (SSGNs). Launch prosecute individual engagements, it could platforms like the Backfire and the Oscar get off multiple shots against the same mis- were armed with supersonic antiship missiles sile raid. of 100-300 mile range. From this distance, In addition to Aegis and the Outer Air SNA bombers and SSGNs sought to launch Battle, the Navy aggressively pursued mea- missiles from outside a Battle Group’s outer sures to counter Soviet ocean surveillance defenses, thus saturating its inner defenses systems at the front end of the engagement with multiple incoming missiles. cycle, as well as a panoply of close in systems Out of this challenge grew the AAW designed to give each Battle Group combat- posture designed to enable the forward ant the ability to defend against antiship mis- Battle Group operations envisaged by the siles in their terminal phase. Maritime Strategy of the 1980s. E-2s and Soviet ocean surveillance systems, which F-14s armed with long range Phoenix by the 1970s included a substantial space- AAMs extended the Battle Group’s outer based component, provide an example of the ring. As important, aggressive efforts were kind of space capabilities that future adver- mounted to provide strategic as well as tac- saries might deploy. It’s photo satellites, tical warning to the Battle Group of an ELINT satellites, and radar satellites used impending SNA attack. Out of this partic- technology that was quite advanced for the ular initiative grew some of the first and time, including systems designed to geolo- most successful tactical exploitations of cate electronic emissions from space, and to national capabilities (TENCAP), including use synthetic aperture techniques to distin- a program which used missile early warning guish between specific ship types. And the systems to detect and track the exhaust U.S. Navy’s response to this system is also plumes of Soviet naval aviation aircraft in instructive, including a reporting system that told ships when Soviet satellites were over- declined dramatically. Second, on the other head, emission control tactics which denied hand, the U.S. Navy aspires to a much more ELINT satellites a signal to exploit, or false aggressive power projection posture than it emitter tactics which put an emitter normal- did during the Cold War. For example, in ly associated with a specific platform on a today’s security environment, in an analogue decoy platform. to what happened in the Pacific during One indication of the success of these WWII after the Japanese fleet was defeated, countermeasures is the fact that the Soviets Battle Groups are expected to conduct pro- were never able to reduce their reliance on tracted, high volume strike operations with- maritime patrol aircraft such as the Bear, in 200 miles of an enemy coast. Surface which of course were quite vulnerable to a combatants will be expected to provide carrier’s outer air defenses. It is important to naval surface fire support to engaged keep this experience in mind for the future, Marines ashore from just over the horizon of because it demonstrates that the mere an enemy coastline.Third, for the foreseeable demonstration of space capability by a future future, these operations will likely occur in opponent, even a very ambitious one like crises or conflicts where there is a great the Soviets deployed during the Cold War, asymmetry in the stakes in the outcome will not necessarily translate into an effective among the contestants favoring the United ocean surveillance system States’ opponent.This will continue to make The Navy was also aggressive in improv- U.S. military and political leaders averse to ing terminal defenses during this period. In human and material loss among its forces. 41 this category were systems like the Close In And fourth, “export or die,” post Cold War Weapons System (CIWS), a self-contained, arms export markets will continue to pro- radar-cued gatling gun designed to detect vide potential U.S. opponents with modern and attack incoming missiles automatically sea skimming, antiship cruise missiles.A fifth as they approached individual ships. Also, change may involve the development of because Soviet antiship missiles were guided land-based ballistic missiles with an anti-ship by small aperture radars in their terminal capability. phase, decoys and jammers were deployed to This environment has already caused a either fool or blind those radars when they fundamental shift in the Navy’s AAW pos- went active. In this context, the Navy also ture, and this posture will need to continue began to reduce the radar cross section of its evolving to stay abreast of this threat. The ships, not to defeat Soviet surveillance essence of this threat today and in the near efforts, but to enhance the effectiveness of future is the specter of supersonic, sea skim- decoys and jammers used against missile ming ASCM attacks in the littoral launched homing radars. from truck-mounted launchers ashore, fast boats, or non-nuclear submarines which Antiship Missile Defense After the Cold evade a Battle Group’s ASW screen. Such War. In the new security environment, the attacks would give individual ship terminal AAW threat has changed in at least four defenses only minutes to detect and attack basic ways. First, the days of large, saturation incoming missiles as they break the radar missile attacks launched at long range by horizon at a distance of only 15-20 miles. platforms with an ocean-wide reach are This threat is already ubiquitous today in over. In that sense, the antiship threat has those operational scenarios where ships must approach within line-of sight of a hostile wartime would extend for at least 20-25 coastline. Coming this close essentially miles, and its outer limits would roughly cor- solves the opponent’s surveillance problem, respond to the 200-300 mile radius limit for and provides sufficient targeting information current, high volume carrier strike opera- to launch truck-mounted, ASCMs down a tions. Outside that radius, an opponent’s view bearing along which lies a U.S. surface com- would be limited to peacetime or crisis oper- batant within 20-25 miles. ations in which vulnerable assets like long In order to extend this threat outward range patrol aircraft are able to operate the 200-300 miles necessary to sharply because the rules of engagement do not limit Battle Group operations, the oppo- allow U.S. attacks against them. This would nent will need to extend its view of the lit- enable an opponent to cue ASCM-equipped toral battlespace by moving its surveillance surface combatants with the speed and assets upwards, and to extend the reach of endurance to trail Battle Groups, providing a its ASM platforms without thereby re- limited but potentially effective “first salvo” exposing them to a Battle Group’s outer capability much like that pursued by other- defenses. In assessing how potential oppo- wise vulnerable Soviet surface ships in the nents will grapple with this challenge, it is Mediterranean during the 1973 Yom Kippur essential to be clear about the problems War. But such a wide area system would not they will face. be effective against Battle Groups which sur- The most important issue is the distinc- vived or were not-exposed to the first salvo. 42 tion between a wartime capability and one Inside a 200-300 mile radius, early in a that functions effectively only in peacetime conflict, Navy surface combatants will face or a crisis.Wide area surveillance of the ocean the prospect of ASCM attacks launched from surface requires putting sensors within rela- land, submarines, or small, fast boats, and tively continuous line-of-sight of the area to cued by elevated, offboard sensors. The ele- be surveilled. In the case of any near term vated offboard sensors, whether aircraft, opponent, these sensors will need to be UAVs, or aerostats, and their command, con- deployed in airspace that will be contested trol, and processing facilities will be protect- during a war. Certainly in the near term, the ed by modern, mobile SAMs able to reach United States will win those contests when some 50-100 miles outward from the oppo- an opponent seeks to operate well outside its nent’s coast, and at elevations of 50-60,000 own airspace.Thus, it will be very difficult for feet, these sensors will have an horizon some time for potential U.S. opponents to stretching some 200 miles. A further step develop and deploy a robust, dedicated, upward in the opponent’s anti-access capabil- ocean-wide or even littoral-wide surveillance ity will occur within 20-25 miles of its coast. system for use in wartime against U.S. naval Within this region of the littoral, an oppo- forces. nent’s ASCM missiles will not need offboard Much more feasible is a system that seeks cueing to be effective, and the opponent’s only to preserve the wartime reach of sur- ASCM launchers will be operating in a high veillance assets out to the “electronic hori- clutter environment in which it will be much zon” of the littoral battlespace as viewed more difficult for the Battle Group to inter- from the opponent’s coastline. Depending on dict or suppress these launchers before they the range and elevation of the sensors used, launch their missiles. In this environment, the highly contested littoral battlespace in extreme pressure will be placed on the inter- mediate and terminal ASCM defenses of the and toward networks that link them togeth- ships comprising a Battle Group. er and process their output more effectively. Thus, the near to mid term antiship mis- There are both immediate opportunities in sile defense challenge will likely resolve itself this regard, and opportunities which demand into three elements corresponding to the further development. This section will look survivability of the opponent’s surveillance at the immediate naval aviation opportuni- capabilities: the opponent’s peacetime sur- ties in the Sea Shield mission area that are veillance system that gives extended reach already being pursued. but is vulnerable; it’s extended littoral system which reaches out 200-300 miles and whose Countering Submarines and airborne sensors can survive as long as the Mines modern, mobile SAMs that protect it remain unsuppressed; and its core wartime system The ASW and Mine Countermeasure prob- which is limited to the 20-25 mile horizon lem in the littorals will always be difficult. from the opponent’s own coastline. But tremendous progress has been made in It is important to note again that the the ten years since the end of the Cold War most serious access challenge faced by the on the main challenges in these areas. Navy in this area comes when it is playing Compared to other warfare areas, ASW and the role of an enabling force for the other MCM pose particular challenges in the areas services. Thus, for example, Battle Groups of sensors and, to a slightly lesser extent, standing off more than 300 hundred miles weapons. Networks are very important in 43 from an opponent’s coast can still launch ASW,but the networking technology need- Tomahawk missiles and long range aircraft ed is less demanding in many ways than the strikes essentially at will once an opponent’s networking requirements in AAW.Networks peacetime surveillance system has been are less important to MCM. destroyed, albeit at a lower sortie rate than when such operations are mounted over a ASW Surveillance Sensors. The primary shorter radius of operation. But naval com- ASW challenge has always been wide area batants will have to close within 20-25 miles surveillance or search, and the main chal- of a hostile shore to provide the naval fires lenge initially posed by the new security that will enable ship to objective maneuver environment in this mission area is a wide (STOM) by Marine Expeditionary Units area search problem. Sound propagates bet- (MEUs), and MEUs will often be the key to ter in deep water than in shallow water, and gaining access to the ports and airfields non-nuclear submarines can remain silent ashore that are necessary for reinforcing for extended periods when allowed to patrol ground and air units. small areas near their home ports at low speed. Using passive acoustics to search for Sensors, Weapons, and such submarines is much more difficult than Networks for Gaining and it was to search for relatively loud Soviet Exploiting Access submarines operating in deep water during the Cold War. On the other hand, active The need to gain and exploit access in the sonars encounter serious problems with new security environment will drive the clutter in shallow water, much as early radars Navy toward better sensors and weapons, did when forced to look down at targets flying over land.And even in shallow water, the trawlers, and using buoys to relay the array water column still remains relatively opaque output directly to ships at sea. to non-acoustic energy, limiting the role of AEER adds commercial off the shelf RF and laser radars as long range sensors. (COTS) processing to existing towed arrays Three systems stand out as first steps on ships (and potentially, submarines) and toward regaining a wide area search capabil- air-deployed sonobuoys, and links the ity in the littorals. The first is called the processors together using legacy radios with Advanced Deployable System (ADS); the modems to form a network that can do second, derived from the Distant Thunder bistatic or multistatic processing of the experiment, is Advanced Explosive Echo echoes from the air-dropped sound source. Ranging (AEER); and the third is the Low The essence of AEER is that it uses both Frequency Active (LFA) variant of the spatial and temporal processing to extract a Surveillance Towed Array Sensor System submarine’s echo from the clutter and rever- (SURTASS).ADS is a passive ocean bottom beration. Long wavelength towed arrays or array that can be deployed by a surface ship, directional sonobuoys use spatial processing and whose output is currently collected and to eliminate clutter and reverberation except processed ashore via fiber-optic cable. on the azimuth of interest, and temporal pro- AEER is primarily a signal processing cessing allows reverberating echoes from the adjunct to existing ASW combat systems, same object to be compared over time, combined with coherent, air-droppable, thereby exploiting the fact that a submarine’s 44 active sound sources and a relatively simple echo loses less of its higher frequency spec- data link that uses existing UHF radios on trum in that time than do objects sitting on participating platforms. LFA is a very power- the bottom or floating on the surface. ful, low frequency active sonar. One of the original concerns from Distant Unlike the Cold War Sound Surveillance Thunder was that variations in bottom topog- System (SOSUS) arrays, which listened for raphy and content would interfere with low frequency, narrow band tonals propagat- AEER’s temporal processing capability, but ing outward horizontally along the deep worldwide experiments have demonstrated sound channel, nodes in an ADS array look excellent performance over a wide range of upward along what is called the Reliable environments. Like all acoustic sensors, perfor- Acoustic Path (RAP). ADS is a derivative of mance will vary in practice depending on the Cold War Fixed Distributed System (FDS) many circumstances, but AEER will significant program, which was an attempt to repair the improve the detection ranges achieved using ASW barrier strategy by using many simple active sonar in the cluttered shallow water passive sensors in an upward looking array that ASW environment. Another benefit of AEER used the reliable acoustic path (essentially the is that it demonstrates long range performance direct path) rather than the deep sound chan- under a wide variety of acoustic conditions, nel. Each sensor would cover a small cone of including the very common case in the littoral the ocean column, and fiber optic cable pro- where sound is refracted away from the surface, vided the bandwidth to network a vast array a condition which drastically reduces the per- of these small sensors and bring their output formance of a traditional, hull-mounted sonar. ashore for processing. Future work on ADS The main challenge facing AEER today is that will focus on deploying the arrays covertly via its recognition differential is low when used by submarine, protecting the arrays from bottom non-laboratory personnel. Finally, both ADS and AEER are also program is developing the capability to great examples of the incredible power of process APS-137 returns in such a way as to networked sensors, and the relative ease of allow very low detection thresholds (i.e. long backfitting such a capability onto legacy range) and very low false alarm rates. Very platforms once the substantial initial chal- impressive results have already been demon- lenge of developing the necessary signal pro- strated in shipboard experiments, but unlike cessing algorithms is completed. Systems like systems like AEER, ARPDD needs further AEER can be backfitted onto any towed development time to reduce the footprint of array ship or submarine, and onto LAMPs the massive processing capability it now helos and P-3s. requires before it can be deployed on surface SURTASS was a late Cold War system ships, maritime patrol aircraft, or helicopters. that used towed passive acoustic arrays to supplement SOSUS coverage, or extend Maritime Patrol Aircraft and Helicopters. coverage into waters too shallow for a deep Long range, persistent, land-based maritime sound channel. SURTASS has been upgrad- patrol aircraft provide the only way for a ed with better passive acoustic capabilities, dominant naval power to maintain a continu- and LFA is an additional update that adds an ous presence and surveillance throughout the active, low frequency acoustic source, trans- vast ocean and littoral spaces over which it forming SURTASS into an active sonar. must exercise control.They often provide the Specialized periscope or mast detection most timely means of response, whether to a radars can also play an important role in the fleeting undersea acoustic contact, a report of 45 ASW search problem. Even during the Cold a suspicious merchant ship, or an important War, Soviet nuclear submarines regularly signals intelligence collection opportunity. exposed a periscope when seeking a torpedo In ASW, because sensor performance is fire control solution against the fast ships of a limited, detection ranges are reduced, mak- Battle Group. And of course radar has an ing wide area surveillance a more asset- important role to play in preventing diesel intensive endeavor. Furthermore, all but the submarines from snorkeling to recharge their very quietest nuclear submarines, produce a batteries. Thus, a combination of speed, and continuous acoustic signature, whereas the radar deployed to search within the limiting best detection opportunities against non- lines of approach created by that speed, have nuclear submarines are both episodic and dif- always been an important ASW tactic against ficult to classify. On the other hand, there is a all submarines. Likewise, radar flooding in close correlation between the steps a subma- which a large area is flooded with RF ener- rine needs to take in order get into position gy so as to set off a submarine’s radar warn- to attack a target, and the operational indis- ing alarm whenever it exposes a mast is also cretions which provide the best detection a traditional tactic against diesel submarines. opportunities for ASW forces. Therefore, But specialized mast detection radars like the contacts must be prosecuted and reliably clas- APS-137 experience tremendous false alarm sified as quickly as possible before they disap- rates caused by both sea state and other float- pear back into the cluttered background as an ing objects and debris when their detection unknown contact. This puts a premium on threshold is set low to maximize range. ASW platforms that can be deployed in num- The Automatic Radar Periscope bers and distributed throughout the sea base, Detection and Discrimination (ARPDD) close a potential contact quickly,and deploy a Among many roles, maritime patrol aircraft and multi-mission helicopters will provide the best means of making opposing submarines pay for their inevitable indiscretions. menu of high quality acoustic and non- during the Cold War is the tradition of rela- acoustic sensors to reacquire and identify the tively autonomous operation amongst the contact, classifying it as a false alarm, or trail- Navy’s main ASW platforms.When the Soviet ing and/or attacking it. Navy finally deployed very quiet nuclear sub- Multimission maritime patrol aircraft and marines near the end of the Cold War, the ship-based helicopters will play an increas- need for more coordination arose. Today, ingly important ASW role in the new secu- coordination is even more important, espe- rity environment because they provide the cially to give the ASW commander and all of best means of quickly responding to surveil- his forces a wide area picture of the ASW bat- lance cues, especially when those cues do tlefield. Such a picture would allow better uti- not include reliable classification of the tar- lization of multiple, often evanescent contacts get, as they often will not. against the same target produced by different sensors; it would give units knowledge of ASW Weapons. Torpedoes remain the pri- environmental conditions over a wide area, mary ASW weapon in the littoral environ- allowing them to better predict the perfor- ment, although this environment also mance of their sensors as they move about the presents them with great challenges, partic- battlefield; and it would identify resulting ularly lightweight torpedoes, which are “fire “holes” in ASW coverage where search assets and forget” weapons. Like all fire and forget could be concentrated efficiently. weapons, the relatively small aperture and Most of the individual pieces of work limited signal processing available to a light- needed to accomplish this task are relatively 47 weight torpedo’s active seeker makes for simple, such as using common operational problems in shallow water where there is a protocols when processing and communi- lot of clutter and the target is relatively small cating data, and using the same environmen- and moving slowly. The Mk. 50 modifica- tal models. But the task is complicated by tion to the Mk. 46 lightweight torpedo pro- the need to integrate these activities across vides an initial response to this problem, and many platforms. the more ambitious Mk. 54 a more robust response in a few years. MCM Sensors. As with ASW, sensor per- There is also an alternative ASW weapon formance is central to success.And again, the opportunity that grows out of the intersec- beginning of the problem is always to detect tion between MCM and ASW. One of the and identify the mines in the first place. In challenges in the organic MCM program is the new security environment, this challenge to do in stride mine neutralization and is further complicated by the need to make clearance from a helicopter, and the Rapid such a mine hunting capability organic to the Airborne Mine Clearance System (RAM- Navy’s forward deployed Carrier Strike ICS) program’s approach to this problem Groups, Expeditionary Strike Groups, and may provide another ASW weapon oppor- Submarines. tunity as well. RAMICS is discussed in The key opportunities in this area more detail below. being exploited today are very compact, imaging sonars and laser radars (LIDARS) A Common ASW Operational Picture. able to detect and identify mines in the One of the legacies of the formidable passive water column and on the bottom. acoustic detection ranges possible in ASW Because these sensors can be made very small, they can be deployed on or towed In addition to influence sweeps, MCM by smaller helicopters such as the CH- forces also must have the ability to individu- 60; put on a surface ship-launched and ally approach and remove or destroy all the controlled, semi-submersible vehicle; or mines it has found, because influence sweeps even inside a torpedo-sized UUV trade off speed for a reduced certainty that a launched and recovered from a subma- minefield has been truly cleared. Here, one rine. Through the regular, peacetime encounters perhaps the slowest and most employment of these sensors, the Navy labor intensive naval warfare area, in which can map the ocean bottom, particularly today’s dedicated MCM force utilizes explo- near key approaches or chokepoints. sive ordnance disposal (EOD) divers, marine Doing so will facilitate the location of mammal systems (MMS), and remotely newly-placed mines, appearing as operated underwater vehicles. “deltas” from the peacetime picture, New approaches to this problem designed allowing forward deployed forces to for use by organic MCM forces focus on rapidly focus on areas to avoid, or if they helicopter-deployed systems. In the nearer are critical, areas to clear. The unique term, a helicopter-delivered, remotely oper- advantage of the submarine-UUV com- ated underwater vehicle will be deployed bination is that this sensing can occur that can approach an already identified mine regularly without raising suspicion. and explosively destroy both itself and the mine. In the longer term, the RAMICS sys- 48 MCM Weapons. Once identified, mines tem described above is being developed. need to be neutralized or destroyed. In RAMICS will combine a LIDAR and a many cases, the instruments that accomplish Gatling gun firing supercavitating, 20mm this purpose are not really weapons, but so projectiles. The LIDAR would be used to called influence devices designed to create search for and identify mines, and the gun’s the signature needed to set off the mine in projectiles would disable or neutralize it by a way that does not destroy the mine penetrating the mine’s shell and injecting a sweeping platform. An influence sweep chemical initiator into it. usually requires a platform that will not itself set off the mine, but which can tow a The MCM Network. Unlike sophisticated vehicle that will, hence the long tradition of networks like AEER, and those that will be relatively small, dedicated minesweeping described below for AAW and strike warfare, ships with low magnetic and acoustic signa- the main network in MCM is human, and tures. More recently, helicopters have been the center of this network is the dedicated employed to tow influence sleds, but the MCM force. This is to say that even more size of the latter has required the towing than ASW,MCM success is not a science but services of heavy lift helicopters like the an art that requires practice and extensive, massive CH-53. Some of the same trends detailed knowledge, and which is therefore which will allow smaller MCM sensors will extremely perishable. A dedicated MCM also allow smaller influence sleds, enabling force is the home for this expertise, because an eventual transition to a CH-60 platform, it is the only place in the Navy where offi- and in turn allowing forward deployment cers will do nothing but train for MCM, and on existing carriers, surface combatants, and where the intelligence on foreign mines will amphibious ships. be sustained. Also, the nature of the entire undersea depth, and depth was naturally provided in warfare threat, and particularly the mine this Cold War mission area by the great range threat, is that its most challenging manifes- at which Soviet sea denial operations against tations have primarily “purple” and “green” U.S. Battle Groups were mounted. consequences. In other words, an aggressive, The main problem with the littoral AAW inshore mining campaign by an opponent threat is that this depth is largely absent, both will more directly impact the projection of because the U.S. Navy seeks to close with its Army and Marine Corps power than it will adversaries, and because those adversaries are purely naval power, and even when the generally constrained anyway to operations Navy does face a serious mine threat, it will within the littoral battlespace. This means usually arise when it is operating in direct that an adversary’s launch platforms will be support of the Marines, as in the NSFS mis- buried in the clutter and noise of the littoral sion. Combined with an aggressive organic environment, either on land or in shallow MCM program, this might lead some to inshore waters where it is easy for them to advocate the eventual dissolution of the hide. It also means that the surveillance sys- dedicated MCM force for narrow bud- tem that cues those launchers need not getary purposes. A salutary warning of the approach ocean-wide coverage, but rather likely consequences of such a decision is must only aspire to cover a radius of several provided by the Air Force’s decision after hundred miles outward from the coast. And the Gulf War to retire its dedicated airborne finally,because ASCM weapon engagements electronic attack and air defense suppression will usually occur over an even shorter range 49 assets in the belief that stealth would make within the contested littoral battlespace, the such a dedicated force unnecessary. specific weapons used can be relatively short range, sea skimming missiles rather than the Countering Missiles high arcing AS-6s and SS-N-19s of Cold War fame. Throughout the Cold War, the main AAW All of these factors conspire to radically threat to U.S. Navy Battle Groups was the compress an AAW engagement in space and long range, air and submarined-launched, time, reducing the role of the outer air bat- antiship missile.This threat presented itself at tle, and reducing the number of shots avail- great distances from the Soviet homeland, able during the inner air battle. For the most and was supported by an ocean wide surveil- serious sea skimming ASCM threats, lance system. The seriousness of this threat launched from platforms that have success- provoked major attempts by the Navy to deal fully approached a Battle Group in the lit- with it at every step in the engagement toral clutter, the AAW engagement will sequence. Efforts were mounted to defeat or begin when the attacking missile approach- fool the surveillance system, to attack the es the targeted ship’s radar horizon—say 20 launch platforms before they could launch miles—and will be over, for better or worse, their weapons, to take multiple shots at the within one or two minutes. weapons themselves if they leaked through a Three interrelated steps are being taken to battle group’s outer defenses, and to defeat counter this threat. First, elevated sensors the weapon’s seeker in the terminal phase need to be developed which can eliminate or with both active and passive countermea- greatly reduce the clutter in the littoral envi- sures.All of these defensive measures required ronment which allows ASCM launchers to hide, and which also prevents missile detec- against relatively high doppler targets, i.e. tion until the terminal phase of an engage- ones closing on the main beam of the radar ment. Second, weapons need to be developed at a relatively high rate. An ability to track that can function in the same cluttered envi- low doppler targets in the littorals is critical ronment against small, fast targets. And third, because both surface ships and aircraft, as these sensors and weapons need to be linked well as ASCMs, will often present them- together in such a way as to allow an elevated selves as low doppler targets. sensor to provide the information needed for Second, mechanically scanned UHF another platform to launch a defensive radars have inherently larger sidelobes than weapon against the incoming weapon from do higher frequency radars, which makes over the radar horizon. them more susceptible to both intentional jamming, and to inadvertent electromagnet- Advanced Hawkeye Will Reduce Littoral ic interference (EMI). EMI is particularly Clutter. Central to the ASCM defense troublesome at the lower, roughly 400 MHz problem is a much better wide area picture of frequencies where the APS-145 operates the littoral air space, particularly at the low because there are so many powerful com- altitudes relevant to the ASCM problem.The mercial occupants near this band. E-2 is the Navy’s primary AAW surveillance The radar on the Advanced Hawkeye will system but it is not currently well equipped defeat these problems using two separate tech- for this task. As a relatively low frequency, niques. First, the APS-145 will be replaced by 50 pure pulsed UHF radar, the existing E-2 APS- a digital, phased array radar called the ADS- 145 radar has tremendous difficulty detecting 18, whose 18 element array will allow elec- targets in the littoral for two basic reasons. tronic scanning over 160 degrees, and which First, more than higher frequency, pulse will mechanically rotate to provide 360 doppler radars like that on the Air Force’s E- degree coverage. The phased array antenna 3, the E-2 has trouble picking out low flying allows the radar to reduce its sidelobes elec- targets over land or among maritime clutter tronically, significantly reducing the jamming because it does not exploit Doppler signal and EMI problem. It also provides more gain processing.This was not a problem in a blue in the main lobe, giving better detection water environment because at UHF the sea ranges. Second, the ADS-18 will also allow surface is a mirror, but in the littoral or over temporal processing by providing three com- land, clutter interferes with the ability to plete sets of measurements of the RF energy detect low flying targets. And even radars returning from a single spot, which will allow that do use Doppler signal processing have it to distinguish the moving target within the trouble with so-called low doppler targets.A fixed clutter background of that spot because low doppler target is one whose movement the target will move slightly during the inter- relative to the clutter background in the val between each of the three pulses. direction of the surveillance radar is low, ADS-18 will provide a quantum leap in either because the target is moving slowly in the ability of the E-2 to detect ASCMs in the absolute terms, or because its direction of littoral environment, as well as a raft of other movement is perpendicular or nearly per- important targets.The next step is for the E- pendicular to that of the radar’s main beam. 2 to provide its track information to shooters Historically, doppler signal processing in in the air and on surface ships in a way that look down radars has been most effective maximizes their ability to shoot down the missile. This can be done in three ways, kinematic range of the interceptor. ERAM roughly corresponding to degrees of both substitutes an active seeker based on the capability and risk, and the Cooperative AMRAAM (but with a larger aperture) for Engagement Capability (CEC) is central to the semi-active guidance of earlier SM-2s. all three. This eliminates the need for an X-Band illuminator within line-of-sight of the target The Centrality of CEC on E-2. CEC is during the end game of the engagement. a very sophisticated data link that allows dif- Instead, using track data provided by E-2, ferent platforms to share track information ERAM will allow engagements where not on targets with a speed and accuracy that only is the intercept begun when the target allows one platform to shoot a weapon at a is beyond line-of-sight of the launcher, but target that another is tracking. In practice, completed as well. CEC enables both very accurate cueing, to provide warning to another platform that it Active Electronically Scanned Antennas is under attack by a target it cannot yet see, (AESA) and Overland Cruise Missile and to maximize that platform’s radar ener- Defense. Just as cruise missiles pose seri- gy management so that it can begin defend- ous threats to ships in the littoral, they also ing itself as soon as possible. More pose threats to targets ashore. Overland ambitiously, it allows for actual over the cruise missile defense presents all the horizon engagements, where one platform problems described above, with the addi- launches a weapon that another guides to tional challenge that the endgame of the 51 the target. In all cases, CEC extends the bat- engagement is more challenging because tlespace available to combat the ASCM small aperture AAMs have more difficulty threat, and this is particularly the case when locating and homing on cruise missiles CEC is combined with Advanced Hawkeye. against a ground clutter background than At a minimum, CEC can give warning to they do at sea. One element in the solu- any ship with terminal ASCM defenses that tion to this more challenging problem is it is going to come under attack from a very the AESA radars that will soon be specific azimuth, allowing it to aim its ship deployed on F-18E/F and, late in the self defense systems at that point on the decade, on F-35. Compared to mechani- horizon and to prepare to deploy decoys. cally scanned radars, AESA radars have For ships with Standard missile or Sea much more capability against low cross Sparrow capability,CEC will provide cueing section targets, both because they detect that allows search radars to focus their ener- them earlier, and because they track them gy on the horizon, and will in some cases more accurately in azimuth and elevation. enable missile launch before the ASCM has Earlier detection gives back battlespace, broken the target ship’s radar horizon. making for more favorable intercept Most ambitiously, when combined with geometries, while better tracking accuracy the SM-2 Extended Range Antiaircraft enables a fighter to guide AAMs like Missile (ERAM), E-2/CEC will enable SM- AMRAAM into smaller baskets within 2 intercepts out to 100 miles, even against which their terminal seekers are more low flying targets, at the very limits of the likely to acquire and home on the target. Airborne electronic attack capabilities will grow, not decline in importance in the new security environment. The Revolution in Sea Strike

Sensors, Weapons, and iled by the following kill chain requirement. Networks for Dealing The targets in question were small and With Mobile Targets mobile and could only be reliably identified by friendly ground forces in close contact ROM THE FIRST USE of military avia- with them; once targets were identified, it tion during World War I until Desert was difficult for friendly ground forces to FStorm, it was common for air-dropped mark them for supporting forces; and once bombs to miss their targets by several thou- targets were marked, it was difficult for sup- sand feet, and it therefore often took several porting air forces to bring a weapon to bear hundred or even thousand strike sorties to that did not simultaneously threaten friend- destroy a single fixed target with conven- ly and hostile forces. Fort McNair is only tional weapons. Precision weapons have one of many monuments to the historic dif- quickly changed that equation so that now it ficulty of closing this kill chain. is reasonable to expect a single strike sortie The keys to completing the solution to to destroy several targets. Furthermore, the the close air support problem are three: the 53 leap from “clear weather” to “all weather” wide deployment among ground forces of precision attack was essentially completed in both laser-based target markers/locators and the brief period between Desert Storm and ground controllers; and the provision of data Iraqi Freedom. This revolution in precision links (rather than just voice links) between has solved the fixed target problem in the ground controllers and combat aircraft. The sense that no opponent of the U.S. can obstacles to this achievement are no longer expect its fixed targets to survive long once technical, and the organizational/doctrinal they have been identified for attack. Of obstacles that blocked progress in this mis- course, nothing about this revolution assures sion area in the past seem to have faded. It is that the opponent’s fixed targets will be dis- in this sense that one can say that the close covered or correctly identified, not is it air support problem is solved, and it is also in assured that effective attacks against fixed tar- this sense that one can say that the mobile gets will have decisive effects, but the simple target problem is not solved. fact that once identified a fixed target can be Solving the mobile target problem will quickly destroyed does represent a revolution require the development and tight integration in capability for U.S. air forces. of new sensors, weapons, and networks for Both Enduring and Iraqi Freedom have linking them together.These will be used to also demonstrated the “solution” to another find, identify, track, locate, attack, and assess vexing problem for air forces; the ability for attacks against various types of mobile targets. air forces to provide effective and timely The mobile targets of concern will include support to ground forces engaged directly opposing armored units and their command with opposing ground forces. Such close air posts, surface-to-surface and surface-to-air support operations have always been bedev- missile launching units, and leadership targets. Sensors,Weapons, and Networks relative to the earth’s surface (90 minute ver- in the Littoral Battlespace sus 24 hour orbits).They see much less of the earth’s surface at any one time, and it might The littoral battlespace for strike opera- take 12 hours for a single satellite to come tions against mobile/time critical targets will within line-of-sight of the entire earth, but remain defined by the border between con- because they orbit so much closer to the tested and uncontested air space, the maxi- earth, such satellites can deploy sensors mum altitude at which combat operations whose power-aperture or resolution product occur, and the maximum range into contest- is insufficient for deployment in high orbits. ed air space that combat operations occur. Historically, satellites have been valuable Within that battlespace, naval strike forces will sensor platforms, particularly for intelligence deploy platforms carrying sensors and purposes, because they provide global cover- weapons, both manned and unmanned. Some age, at least intermittently,and because space of these platforms will be multi-purpose, was not seriously contested as a deployment while others will have a single purpose; some medium during the Cold War. By contrast, will be autonomous, while others will be airborne platforms must operate in or along- closely controlled from other platforms; some side contested air space in order to come will need to send and receive large quantities within line-of-sight of their targets. In cases of sensor data, while others will have less where enemy defenses have not been sup- stringent need for high bandwidth connectiv- pressed, and where airborne sensor platforms 54 ity; and finally,these platforms will vary in the are vulnerable to attack, they must patrol degree to which they can survive indepen- outside contested airspace and look hori- dently in the face of opposing defenses. zontally across the battlefield.The maximum The capabilities of sensors, and the plat- theoretical detection range of almost any forms they are deployed on, have the largest sensor under these circumstances is the dis- impact on strike operations.The sensor plat- tance to the horizon, or the distance of a forms supporting future strike operations will tangent drawn between the platform and the primarily use radar, signals intelligence or earth’s surface. For air breathing platforms, SIGINT (defined here as the passive collec- the maximum altitude of operation is about tion of either communications, or COMINT, 60,000 feet, leading to a maximum detection or opposing radar emissions, or ELINT), and range of about 250-300 miles. optics exploiting either visible light or This is significantly less field of view than infrared. They will generally be deployed on even a satellite in low earth orbit, which can either satellites or airborne platforms. see upwards of 500 miles outward along Space-based sensors look down at their either side of its ground track. But an air- targets from low (~200 miles), medium borne platform can orbit for many hours or (~11,000 miles), or high (~22,000 miles) even several days within line-of-sight of the orbits. Satellites in high orbits remain in the same battlefield, whereas continuous cover- same position relative to the earth as it age of the same battlefield from low earth orbits, providing continuous coverage of the orbit requires a constellation of many tens of same quarter to a third of the earth’s surface, satellites in order to ensure one will always meaning that three or four satellites can pro- be within line-of-sight. Alternatively, air- vide continuous global coverage. By con- borne platforms and satellites in high orbits trast, satellites in low orbits move much faster both provide continuous coverage of the same battlefield, but airborne platforms pro- radar might have a maximum range of 50 vide this coverage at distances that allow the miles. Passive optical sensors usually have use of sensors whose power-aperture prod- shorter ranges than radars, with even the uct is inadequate for deployment in high widest aperture airborne systems usually not orbiting satellites. exceeding 50 miles, and active optical sen- In reality, maximum and realistic detec- sors such as laser radars (LADARS) have the tion ranges are almost always different. In the shortest ranges of all, with most airborne discussion that follows, I will look at the ladars limited to approximately 5 miles. actual limits on the performance of sensor Measured in terms of resolution or accu- platforms, focusing on those deployed on air- racy, sensor performance is generally invert- borne platforms. When the discussion shifts ed, with very high frequency visible light to how those sensors will be used in future sensors and LADARS providing the most sea strike operations, I will bring space-based accurate bearings and ranges, and the sensor platforms back into the discussion. sharpest images, followed closely by IR sen- As noted above, the maximum detection sors, with the performance of radars and range of a sensor is determined by its dis- SIGINT systems lagging behind in those tance from the horizon. In practice, maxi- performance metrics because of the much mum detection ranges often are lower frequencies of the signals they exploit. considerably less because performance Finally, sensors vary according to how depends on the diameter of the sensor’s they are affected by weather, battlefield antenna or aperture, and the power available obscurants like smoke, ambient light levels, 55 to it – both of which consume weight and foliage, and physical obstructions like terrain volume, which are always scarce on airborne and buildings. SIGINT sensors and radars are platforms and extremely scarce on space- least affected by these factors, though the sig- based platforms. Also, for a given wave- nals they collect can be blocked by major length, aperture size and design determines terrain obstructions, and radars do not pene- the angular resolution of the sensor, or the trate foliage well. By contrast, optical sensors accuracy of the bearing to the target it pro- are dramatically affected by all or most of vides. Again, for a given wavelength, passive these factors. Neither IR or visible light sen- sensors have longer range than active sensors can see through cloud, and in addition, sors, but on the other hand, active sensors visible light systems are quickly blocked by can provide range to the target, whereas pas- obscurants such as smoke and become much sive sensors provide only a bearing. less effective in low light conditions. As a rule, SIGINT sensors are the only Within their detection ranges, and given ones whose detection ranges will always the limits on their resolution, different sen- extend out to the horizon, which on an air- sors perform different functions. SIGINT borne platform will be 200 or more miles. sensors detect radio or radar transmitters and For radars and optical sensors, detection provide a line of bearing to them, with more range will depend more heavily on aperture sophisticated systems also providing an and power, and therefore on volume and analysis of the signal that allows identifica- weight. For example, JSTARS’ radar has a tion of the class of the emitter, and in some maximum range of about 150 miles against cases, the specific emitter itself. Such systems a ground target, while Global Hawk’s is can also be used to develop an estimate of more like 100 miles, and a current fighter’s the location of the emitter by taking multiple lines of bearing from several look angles, as soon as it stops moving, and then imme- but these estimates do not provide a precise diately picked back up on MTI once it starts location (<100s of meters) because of limits moving again, but this capability will soon on the angular resolution of the bearings. be deployed and will improve the ability of Radars detect objects with sufficient SAR/MTI radars to maintain continuous reflectivity (radar cross section) to provide a tracks of specific mobile targets. detectable return. When airborne radars Today,passive optical sensors are used pri- look down, terrain features provide a flood marily to collect very high resolution images of returns that are difficult to distinguish or lower resolution video, and lasers are used from each other without specialized process- primarily as range finders and target illumi- ing of the return signal. Today, in air-to- nators. In the not too distant future, ground operations, the primary radar modes LADARS will be deployed that will be able are synthetic aperture radar (SAR) and mov- to “measure” targets very precisely in three ing target indicator (MTI). dimensions, albeit at relatively short range. SAR uses the movement of the radar One other metric related to sensors con- platform over time to create an artificially cerns varying demands on processing capabil- wide “aperture” or antenna that can be used ities and downlinks. SIGINT sensors used in to produce higher resolution images of a peacetime to collect and analyze signals fixed target than could be produced using require large amounts of signal processing. the real aperture of the platform’s radar That processing can either be deployed on a 56 antenna.With SAR, a radar gains an imaging large manned platform, such as an RC-135 or capability with resolutions that approach but an EP-3, which is thereby able to perform its do not equal those normally provided only primary mission autonomously, or it can be at much higher optical wavelengths. By con- separated from the sensor platform by a data trast, MTI exploits the relative movement of link, allowing the use of smaller sensor plat- a moving target normal to the path of the forms like U-2 or Global Hawk, which can fly radar platform. It does this by exploiting the higher and longer, but which must downlink fact that radar pulses reflected back from a their output to a command center with the target moving toward the radar have a high- requisite processing capabilities. The required er, or doppler shifted, frequency than the data links must be wideband, with data rates pulses reflected from the stationary back- measured in the multiple megabit/sec range, ground around the target.With doppler sig- and can either be line-of-sight, to a command nal processing, the radar can therefore be post within less than 200 miles or so, or via instructed to “see” only moving targets, and satellite, in which case they could link any- the background clutter can be filtered out. where, albeit at lower data rates than the max- When the two signal processing modes imum available using line-of-sight links. are combined, a SAR/MTI radar can detect One of the main purposes behind peace- and track moving vehicles over a wide area time SIGINT collection and analysis is to using the MTI mode, or provide high reso- form libraries of the characteristics of com- lution images of a series of spots within that munication and radar transmitters of inter- area. SAR/MTI radars do not yet interleave est.These libraries, or portions of them, can these two different modes rapidly enough be loaded onto discs and carried on essen- such that a target detected using the MTI tially any platform. During combat opera- mode can be imaged using the SAR mode tions, SIGINT surveillance assets use these libraries to generate immediate threat warn- links from the U-2 or Global Hawk radars ings of emitters within their field of view are wideband, multi-megabit/second links. that require very little processing, and that Optical sensors generally do not require as can be broadcast on low bandwidth links. much signal processing, but their require- Today, large, sophisticated, intelligence plat- ments for data transmission vary according to forms are generally used in this role, but not the resolution desired, whether the imagery is because of the need for their substantial pro- still or video, and whether it needs to be cessing or data link capabilities. transmitted in real time. Real time transmis- For example, assuming the provision of a sion of high resolution video requires enor- digital threat library,a small UAV with a pas- mous bandwidth, whereas still images and sive receiver, very little onboard processing low resolution video can be transmitted in capability,and a narrowband data link would real time over narrowband links. be able to provide real time threat warnings of hostile radars within its field of view. Quickly Detect, Identify, These warnings would include a classifica- Track, Locate, and Assess tion of the emitter type, the exact time of Attacks on Mobile Targets arrival and frequency of the intercepted signal, and a rough bearing to the emitter’s Successful attacks on mobile targets depend location. Future networks of such UAVs on networks of sensors that can quickly per- might also provide immediate and precise form the tasks described above. Each step in location of threat emitters without signifi- this sequence creates different demands that 57 cant additional processing or data link will be reviewed below, but there are also requirements, as I will discuss in more detail some common challenges. First, mobile tar- below.The point here is to note the dramat- gets will gain significant operational sanctu- ically different requirements for processing ary if sensor networks do not function in and data downlinks between tactical SIG- most weather conditions.This means either INT surveillance operations that exploit that sensors must be chosen that can operate already existing threat libraries, and the through clouds, or that sensors must be peacetime SIGINT collection operations deployed on platforms that operate beneath that generate and maintain those libraries. the weather. Second, sensor networks must The requirements for processing and data either be designed to operate in the face of downlinks for SAR/MTI radars are similar opposing defenses, or those defenses must be to those of peacetime SIGINT collectors. suppressed or destroyed, thereby creating They can either be deployed on large sanctuaries from which sensor networks can manned platforms, where most of the pro- safely operate. This tradeoff applies equally cessing is done onboard by human opera- to the nodes of the network– the sensor tors, such as on JSTARS, or on smaller platforms themselves – and to the data links manned or unmanned platforms such as U- that connect them. 2 and Global Hawk, which downlink their data continuously to ground-based process- The Effects of Weather and ing centers.The processed radar output from Defenses a platform like JSTARS, consisting of SAR images and MTI tracks, can be transmitted As a rule of thumb, the altitude band between using narrowband links, whereas the down- 15-20,000 feet is a good demarcation point regarding both weather and opposing of military voice and data links at VHF and defenses. Above that altitude, sensor plat- UHF using small, low gain antennas, partic- forms will often be above significant cloud ularly on aircraft and ground vehicles. The formations, but at the same time, they will relatively large amount of power available at also be at heights that force the opponent to these lower frequencies also explains why use longer range air defense systems that must satellite communications are possible at use radar for initial weapon cueing and guid- UHF with only slightly higher gain antennas ance. Below that altitude, clouds will be less that need only be pointed at the sky to trans- common, but at those lower altitudes, sensor mit or receive, and can still be deployed on platforms will face shorter range air defenses almost all platforms, albeit at much lower that can engage targets using only passive data rates than are available using line-of- optical sensors, and are therefore essentially sight links (50-100 kb/sec versus mb/sec). immune to suppression or destruction. The tradeoff that comes with depending Of course, against a capable opponent on these simple VHF and UHF circuits is whose longer range air defenses have not that they are inherently vulnerable to jam- been suppressed or destroyed, there will be ming by any transmitter within line-of-sight no operational sanctuary for airborne plat- of the receiving antenna. VHF and UHF forms above the battlefield. Under such cir- communication systems are not friendly to cumstances, if sensor networks have to the two main methods for dealing with jam- operate against unattrited defenses, sensor ming – high gain antennas and spread spec- 58 platforms will need to operate from distant trum or frequency agile waveforms – because horizontal standoff ranges or from space, or both of these antijam methods are best sensors will need to deploy on very stealthy implemented using much higher, microwave platforms that can not be detected or target- or millimeter wave frequencies. ed, or on platforms so cheap that redundant High gain antennas with highly direction- numbers can be deployed in a self forming al reception patterns “ignore” energy that is and self healing network that can sustain not in their main beam, greatly reducing the losses and still function reliably. area from which an opposing jammer can Data links have different vulnerabilities insert spurious energy into the antenna. compared to sensor platforms. Unlike radars, Special waveforms that rapidly vary transmis- whose antennas are always designed to max- sion frequencies or use low power signals imize transmission and reception efficiency buried seemingly randomly in the back- in a specific direction, radio communication ground noise attack the jamming problem systems often use omnidirectional, or low both by making communication signals gain antennas. Such antennas are smaller covert and by making it difficult for the jam- than high gain antennas and also eliminate mer to know what frequency to jam. Jam the need for accurate pointing. Both of these resistant communication systems depend on characteristics make them useful for mobile both these techniques, and both require the platforms where weight and volume are at a use of higher SHF or EHF frequencies premium. Even though such antennas are because high gain antennas at UHF would be much less efficient, sufficient power can be too large for mobile platforms, and because generated except at the highest microwave sophisticated, jam resistant waveforms are frequencies to establish reliable one way prodigious consumers of bandwidth that is links out to the horizon. Thus the ubiquity scarce at UHF. And finally, when bandwidth at the higher frequencies is used to buy jam A possible solution to this problem would resistance, data rates remain the same as on be a laser satellite communication system, today’s links – kb/sec using satellite links and using laser uplinks and downlinks. Lasers suf- mb/sec using line-of-sight links. fer from significant propagation losses in the The issue of data link hardness and relia- atmosphere, but so much bandwidth is avail- bility is central because upon this question able at optical wavelengths that it may still turns the design and viability of any concept prove possible to provide extremely high data of operation that includes a battlefield sensor rates. At the same time, because of the network. Absent jam resistant data links, it extremely high frequencies involved, the will always be necessary to design in default beams produced are extremely narrow,which modes where the network is unavailable and means that even a receive antenna in high individual platforms must perform orbit might be able to null signals emanating autonomously. In addition, assuming jam from outside a narrow cone surrounding the resistant data links are pursued, their devel- legitimate transmitter. Absent the successful opment will need to be tightly integrated development and deployment of such a sys- with the development of the sensor nodes in tem, satellite links will always present a harsh- the network because of the impact that jam er tradeoff between data rate and jam resistance has on data rates, particularly for resistance than will line-of-sight links. satellite links. For example, the performance Assessing the potential physical vulnera- of unmanned or lightly manned sensor plat- bility of space-based sensors and communi- forms like Global Hawk and U-2 that cation satellites is a special case. Heretofore, 59 depend on multi mb/sec or even gb/sec satellites have enjoyed a virtual sanctuary satellite links if there are no ground-based from attack. No war has ever been fought command centers within line-of-sight will between a country with satellites and not degrade gracefully if forced to fall back another with anti-satellites, never mind a on narrowband data links, whereas manned war between two countries with both capa- sensor platforms that do a lot of onboard bilities.Though both superpowers deployed processing of data could adapt much more direct ascent anti-satellite systems during easily to such an environment. the Cold War, neither chose to use them It is unlikely that jam resistant satellite against the other in peacetime, and the communications will ever provide the absence of war between the superpowers same data rates available using line-of-sight leaves open the question of whether these links. The receiving antenna in a line-of- systems would have been used in a war. In sight downlink will normally be able to any case, neither side’s anti-satellite systems shield its sidelobes from jamming signals, were very extensive, nor did they have the whereas receive antennas on high orbit capability to reach beyond low earth orbit. satellites are much more exposed. This Before attempting to judge the future means that jam resistant satellite links will relevance of this complicated issue, one always depend on a high degree of spec- needs to ask what role satellite-based sensors trum spreading that comes at the expense or communications systems are likely to of data rate. Today, when sensor platforms play in the future in finding, identifying, use satellite links, they use commercial tracking, locating, or assessing attacks against links designed to maximize data rates that mobile targets. have no jam resistance. Surveillance radars in medium orbits, where many fewer satellites would provide continuous cover- Surveillance systems are characterized by age, but where power/aperture products large fields of view and persistence. Ideally, a would need to be much greater.A third and surveillance system can continuously moni- technically more challenging alternative has tor the entire battlefield and pick out targets therefore emerged envisioning a bistatic or of potential interest with a low false alarm multistatic system in which a satellite in rate. But even the best surveillance systems medium orbit serves only as the transmitter gain this capability at the expense of the in a network in which an airborne platform ability to identify, track, precisely locate, or platforms deployed within line-of-sight of and/or assess attacks against those potential the area of interest serve as the receiver. targets.Thus, historically at least, surveillance The theoretical advantages of such an systems serve a cueing function for other architecture are several. First, it would reduce sensors which complete the kill chain. the cost of achieving continuous coverage The surveillance challenge against an from the sanctuary of space without forcing enemy’s forces in the field largely boils down the satellite designer into a power/aperture to the problem of detecting vehicles.This is race that might not be winnable, particularly obviously a difficult problem, both because when using the MTI mode. Second, despite military vehicles are hard to distinguish from this concept’s continuing dependence on air- other vehicles, and because all vehicles are borne platforms, it would not be as vulnera- 60 difficult if not impossible to detect from a ble to opposing defenses as a purely airborne distance if they are not moving, emitting a system because the airborne platforms in signal, or launching a weapon. question would be passive receivers only, and Moving vehicles can be detected by MTI therefore, in principal, highly stealthy and radars in all weather at ranges that depend able to operate deep within rather than on the altitude and aperture of the sensor. alongside contested air space.Third, if imple- Future airborne surveillance platforms mod- mented as a multistatic system with several eled on today’s JSTARS, U-2, and Global airborne platforms within line-of-sight of the Hawk will be able to detect targets out to same area of interest, such a concept would 150 miles or more. On the other hand, faced also enable the precise tracking of mobile tar- with reasonably advanced air defenses, such gets by exploiting trilateration, or the reduc- platforms need to standoff some 100 miles tion in angular resolution errors of single until those defenses are destroyed. platforms by calculating the intersection of The desire to escape this tradeoff is one the error ellipses of two or three widely sep- reason why a space-based radar program is arated platforms tracking the same target. being pursued. In principal, a constellation One of the challenges with space-based of such satellites could be deployed that radar is that it will be an expensive system, would provide continuous coverage of the meaning that it will need to accommodate earth within its orbital planes. Deployed in the requirements of both the Intelligence low orbit, such a constellation would need community and the Department of Defense, to include 20-40 satellites to ensure that one but these requirements will be difficult to is always above the horizon.The expense of reconcile. The Intelligence community’s such a constellation has led to exploration of prime interest is in a system that provides the alternative of deploying space-based global coverage in peacetime but is less determined than DOD that that coverage be main beam, and, because they are closer, it is continuous, whereas DOD is most interest- easier for them to detect a radar’s sidelobes. ed in continuity of coverage and might be Like radars, SIGINT sensors provide a willing to sacrifice the loss of peacetime line of bearing to their targets which have access to deep inland areas that would result errors in angular resolution of one, several, from adoption of a multistatic system. or tens of degrees, depending on the quali- Vehicles can also be detected when they ty of the receiving antenna and the frequen- use a radio or a radar. SIGINT systems cy of the signal, but unlike radars, a SIGINT designed to detect these signals have longer receiver can not by itself provide a precise detection ranges than radars because the sig- range to the target because it is passive. On nals they collect are more powerful, not hav- the other hand, because most emitting tar- ing suffered the attenuation of a two way gets are stationary while they emit, a SIG- trip in which the power of the signal falls as INT platform can calculate an estimated the fourth power of the distance traveled. range to the target over time by taking mul- Thus, for example, airborne SIGINT collec- tiple, separate bearings on the same signal. tors such as RC-135, EP-3, and Guardrail But in no case would the resulting position can see further into contested air space than estimate have an error ellipse with a radius can airborne radars. less than 100s of feet. At the same time, the signals that SIGINT Finally, a vehicle can also expose itself to sensors collect are often highly directional. detection by launching a weapon, particu- This applies with special force to ELINT larly a missile or a shell. Radars can some- 61 sensors that collect radar signals. Since a times detect such weapons soon after they radar’s main beam sends out a much more take flight, and if they are flying anything powerful signal than do its sidelobes, and approaching a ballistic trajectory,an estimate since that main beam is usually aimed at the of their launch point can be quickly calcu- horizon and scanned in both azimuth and lated. When a vehicle launches a weapon elevation, the probability of detecting the with a strong IR signature that lasts for radar’s signal can vary significantly depending more than a few seconds, it can often be upon where the ELINT receiver is. detected and tracked by missile warning Thus, airborne ELINT sensors have a satellites in high orbits, both giving warning major advantage over satellite-based ELINT to those in the estimated impact area, and sensors when used in a tactical setting. First, allowing a rough estimate of the launch and most generally, an air defense radar’s point, and therefore of the launch vehicle’s main beam will rarely be aimed directly at a location if it has not moved. In principal, IR satellite because the air defense radar will be sensors could be deployed on airborne plat- oriented horizontally to the horizon, forms and used for similar purposes. whereas even a low orbit satellite will nor- In no case can an individual surveillance mally be looking directly down.This means sensor complete the kill chain against a that space-based ELINT systems must be vehicle using the same methods it used to capable of detecting a radar’s sidelobes if detect it. None of the sensor modes they are to routinely and reliably detect it. described above can precisely locate a vehi- Airborne ELINT systems have a double cle; instead, they provide estimates of loca- advantage in that it is much easier for them tion with a radius of uncertainty measured to place their sensors in the path of a radar’s in 100s or 1000s of feet. An MTI radar on an airborne platform can provide a continu- because the accuracy of the attack depended ous track of a moving vehicle within its field on how accurately the attacking aircraft of view, but a space-based system can only could calculate its position and rate of clo- do so if its constellation is designed always to sure relative to the target, not that target’s have a satellite in view.Also, MTI radars can absolute position. not normally classify their targets, at least This did not change with the early gen- beyond such basic distinctions as between a eration of precision weapons. Weapons like tracked or a wheeled vehicle. This may Paveway 1, Walleye, or Maverick did not change with the further development and need to know the absolute position of their deployment of MTI radars that can image targets. Rather, they went where they were moving vehicles when those vehicles are told to go by the pilot, who still found the generating rotational movement relative to target using methods basically similar to the radar, i.e. when rounding a turn on a those described above. It is the introduction road, but the images generated will not be of GPS-guided weapons that has driven the high resolution. SIGINT sensors, on the need for precise geolocation of targets, with other hand, will be able to classify their tar- errors measured in the 10s of feet rather gets immediately upon detecting them than 100s or 1000s, and future weapons like because of the wide deployment of already- small diameter bomb may create the developed specific emitter identification demand for even greater precision. capabilities. Finally, none of the sensor There are two fundamental approaches to 62 modes described can reliably assess the precise geolocation: one involves using net- results of the attacks that result from their works to compensate for the inaccuracies of initial detections. Solutions to the rest of the individual sensors operating autonomously, kill chain will depend on some combination while the other compares images of a target of networking among surveillance sensors collected by a single platform to a database of and the introduction of imaging sensors. geo-registered imagery (or precise terrain data). Networks can be used to compensate for Geolocation the current inaccuracies of both SIGINT and MTI platforms. For example, in the case Even during the latter part of the Cold of ELINT, if three ELINT antennas are War, target location errors measured in the deployed within line-of-sight of a radar and thousands of feet were acceptable because data-linked together, they can be used to an attacking aircraft only required knowl- measure the time of arrival of a single radar edge of a target’s position relative to it, not pulse at three widely separate locations.With the target’s absolute position. Manned air- three receivers, there are three separate pairs craft used their navigation systems to fly to of receivers and the output of each pair can within line-of-sight of the estimated loca- be used to form a hyperbola of uncertainty tion of the target.As long as the accumulat- along which the emitter lies. With three ed error in estimated target location and in hyperbolae, there is only one point at which navigation system performance was less than all three intersect and that point can be the field of view of the aircrew, they had a located with accuracy measured in 10s of good chance of acquiring the target visually feet. More ambitiously, if only two receivers or with their radar. Once acquired in this are available, and at least one is moving rela- way, the target location error was irrelevant tive to the emitter, both the time of arrival and the precise frequency of the received sight of a moving target and data-linked signal can be measured.The difference in the together, the error in target location caused signal’s time of arrival at the two platforms by errors in azimuth resolution can be great- can be used to form one hyperbola of uncer- ly reduced by fusing the error ellipses gener- tainty, while the difference in the doppler ated by each radar and finding their shift of the signal at the two platforms can be intersection.This allows moving targets to be derived to form a curved line intersecting tracked by MTI radars with an accuracy with the first hyperbola at only one point. approaching that needed to target a GPS- ELINT or COMINT networks using guided weapon. As with the SIGINT net- time difference of arrival or frequency dif- works described above, the area in which a ference of arrival (TDOA/FDOA) signal network of MTI radars can precisely locate processing do not require high data rate moving targets is limited by the area in links, but they depend on very low latencies, which the coverage of all three radars over- and the performance of these networks lap, and by the geometry of the radars rela- varies according to the geometry of the sen- tive to the targets within that area. Thus, in sors relative to the emitter and the distance both cases, the performance of the network of the sensors from the emitter. The ideal degrades if its nodes are forced to standoff geometry has the sensors relatively close to from contested air space. For example, when the emitter and essentially surrounding it. standing off in line abreast formation net- One of the great strengths of these networked to precisely locate moving targets, works is that they do not require sophisticat- three widely separated MTI radars able by 63 ed, large aperture antennas. This means that themselves to see 150 miles into contested there is great flexibility in designing the air space might collectively cover an area nodes of the network. For example, where roughly 50 miles deep, and their line abreast groups of aircraft are already present on the formation relative to the targets would also battlefield for other reasons, it will be possi- reduce the network’s location accuracy. ble to turn them into a TDOA/FDOA net- This point illustrates one significant dif- work via Link 16 or its successor using their ference between SIGINT and MTI radar Radar Warning Receivers (RWR) as the networks when used to locate ground tar- network nodes. In addition, because the gets in contested air space. MTI radars put antennas can be so small, TDOA/FDOA much greater demands on their platforms nodes could be deployed on UAVs much for power and volume than do passive SIG- smaller than those required to deploy radars. INT sensors, which means that it should be Thus, because the nodes are passive, and much easier to create SIGINT and especial- because they can be deployed on very small ly ELINT networks that use small, stealthy, platforms, a small UAV-based ELINT net- and persistent platforms that can penetrate work might prove to be the best means of and operate within the coverage area of targeting the radars of advanced air defense unattrited, advanced air defenses. systems. Even more ambitious would be an The other general method of obtaining ELINT network whose nodes were covertly precise target locations is to collect images of placed unattended ground sensors. the potential target, compare them to an Networks can also be used to compensate imagery database which is already geo-regis- for MTI radar errors. If three widely sepa- tered, and match the images collected to the rated radars are deployed within line-of- database. Databases now exist that provide precisely registered optical imagery and ter- identifying targets before attack, and of rain elevation data to which can be compared assessing the results of an attack. images collected on the battlefield by cameras Furthermore, depending on the rules of and SAR radars respectively.The term of art engagement and on the future trends in for this process is called mensuration. technology, it may be the case that many or Today, mensurated optical and SAR most targets will continue to require imaging images are produced on the ground after air- sensors for both classification and damage borne platforms like U-2 or Global Hawk assessment, as they almost always do today. or other national systems have downlinked Certainly, there are instances on the bat- raw, very wide bandwidth data to ground tlefield when classification and/or damage stations where the data is processed, or they assessment can be gained by other means. are produced aboard larger, manned plat- For example, as was discussed above, SIG- forms like JSTARS and the Navy’s experi- INT sensors can classify emitters without mental “Hairy Buffalo” aircraft, which can needing an image, though they can not per- mensurate SAR images on board. Either form damage assessment beyond noting that approach today can require more than an an emitter has gone off the air. Some kinds hour to get targeting information from the of mobile targets essentially classify them- sensor platform to the weapon platform. selves by moving en masse in response to Major efforts are already underway to battlefield events, such as an armored unit reduce the time late associated with target moving to (or retreating from) an engage- 64 mensuration in order to speed up the process ment.Thus, in the case of MTI radars, targets of striking mobile targets while they are at or groups of targets can be sometimes classi- rest. One initiative is to give strike fighters fied simply by the fact that they are where and bombers an organic capability to mensu- they are when they are doing what they are. rate images found by their own sensors. The same caveats apply to damage assess- Another more ambitious goal is to create air- ment, where, for example, there will always borne networks in which UAVs or UCAVs be occasions in which a target’s destruction can downlink optical and SAR images by is easy to determine simply because of sec- line-of-sight links to manned platforms capa- ondary explosions that can be seen from ble of doing the mensuration. The manned great distances. aircraft could be command posts like the Air But the fact remains that a significant Force’s MC2A or the Army-Navy Aerial number of mobile targets will likely remain Common Sensor or individual strike fighters which, by dint of their proximity to friend- like F-35. In either case, the objective will be ly troops or sensitive non-military facilities, to locate mobile targets precisely in real time their high value, or some other factor, will so that once found and identified they can be need to be precisely identified using high struck before they move again. resolution imagery before being attacked, and an assessment of those attacks will often Classification and Damage need to be performed using the same means. Assessment Target classification and damage assessment are important for other reasons. Absent Imaging sensors are one of several means of a process that leads to fairly rapid classifica- obtaining precise target locations, but they tion, surveillance sensors quickly become are often the only means of classifying or swamped because they detect many more potential targets than they can track. In immediately prior to detonation to relay its addition, absent reliable classification, false position, a health and status message, and an targets are generated, wasting valuable track- image of the target area via line-of-sight ing time and causing the diversion of relay back to its launch platform. In the case weapons and weapon platforms. Also, when of attacks against mobile targets, the purpose reliable damage assessment is not available, of the image would be to simply confirm or multiple weapons must be assigned to high deny the presence of the vehicle in the tar- value targets to compensate for the possibil- get area, and its resolution could therefore ity that one might malfunction. And in the be quite modest. particular case of attacks against opposing Today, imagery of relatively high resolu- defenses, a lack of reliable damage assess- tion is routinely generated by optical, ment prevents U.S. forces from exploiting infrared, and SAR sensors, but the perfor- successful attacks. This is a particular prob- mance of these various sensors varies wide- lem in the case of attacks against air defense ly according to their maximum range and radars where, absent damage assessment, a resolution; their performance at night, in successful attack is indistinguishable from a bad weather, and in the presence of battle- successful shut down by the opponent. field obscurants; the weight, volume, and Beyond the common need for imagery, power requirements they impose on their classification and damage assessment may platforms; and their technical maturity. require different degrees of resolution. Optical sensors have the best resolution, Whereas 1 meter resolution might be suffi- they can be given good detection ranges 65 cient to distinguish military from commer- when provided modest aperture, and the cial vehicles, and perhaps even certain types technology of electro-optics is advancing of military vehicles from each other, 1 foot rapidly, making the processing, storage, and resolution might be required to distinguish transmission of optical images easier by the friendly tanks from hostile tanks, or to dis- day.But optical sensors are shut down com- tinguish different variants of the same basic pletely by weather and some important bat- prime mover, such as the missile TEL, radar, tlefield obscurants, and are greatly degraded and command post vehicles within a SAM- at night. IR imaging systems are approach- 10 battery. ing optical systems in their range and reso- At the same time, determining damage to lution, which has had a dramatic impact on a target can require even higher resolutions, strike operations at night, but IIR systems measured in inches, especially when vehicles are also shut down by weather.Thus, as tools are attacked by penetrating weapons that of classification and damage assessment, leave only a small hole, or by sub-munitions EO/IR sensors must be deployable “under which sand blast the outside of the vehicle the weather” if they are to be routinely but leave its basic structure intact. On the available. This reduces their field of view, other hand, to avoid the need for such high increasing the number of platforms needed resolutions, damage assessment can be perfor wide area coverage, and also exposes formed probabilistically using much lower those platforms to unsuppressed, short range resolution images. For example, following air defenses. the model anticipated for AARGM/ These constraints already have led to Quickbolt, any GPS/INS weapon with a efforts to improve the resolution of SAR terminal seeker could be programmed radars, which are “through the weather” systems.Today, SAR imagery of 1 foot resolu- the capability of the both the supporting tion and slant range of more than 100 miles sensor network, and on opposing defenses. is generated by a variety of platforms, and For example, during World War II, air forces imagery with 4 inch resolution has been gained a mobile target capability when they demonstrated, albeit from a slant range of gained sufficient air superiority over the only 25 miles. It is important to note that enemy’s fighters to fly patrols over the oppo- the resolution of SAR radar imagery is nent’s army in the field.When that army was determined less by its angular resolution, forced into large scale maneuver by friendly which is not limited by its real aperture, as in ground forces it filled up the local road net- other radar modes, but by its range resolu- work and aircraft flying very low and using tion. Range resolution, in turn, is limited short range cannon fire, bombs, and unguid- today by atmospheric distortion of individ- ed rockets could relatively easily find and ual radar pulses, the degree of distortion attack such columns. Deployed in the num- varying directly with slant range.Thus, with bers and with the degree of air superiority respect to high resolution SAR imagery,and achieved by the Allies in the campaign to unlike MTI radar, standoff platforms can not liberate France, tactical air forces wrought use aperture to compensate for distance, havoc on the German Army at places like meaning that smaller penetrating platforms Mortain, where a German armored counter- with smaller apertures will have an advan- attack was stopped from the air, and the tage in resolution. Argentan-Falaise gap, where a German 66 Finally, work is being done to give MTI Army was decimated as it sought to escape radars a better capability to identify moving encirclement by allied armies after they had targets. One technique exploits the excellent broken out of Normandy. range resolution of these radars to form a The wide deployment by the early 1970s crude image of the moving target, a tech- of vehicle-mounted, radar-guided, 20 and nique that is also being developed for 40mm AAA and hand held, heat seeking advanced air-to-air radars. A second tech- (infrared or IR), surface-to-air missiles nique inverts the SAR radar’s normal routine (SAMs) greatly raised the cost of all low alti- by using the target’s motion to exploit the tude attacks, whether against fixed or mobile doppler effect of an object rotating relative to targets, and drove attacking aircraft to higher the radar, and to again provide an image of a altitudes. At these altitudes, smaller, mobile moving target, a technique long used by the targets were much more difficult to find and Navy to identify ships at sea. In neither case identify, even when they were concentrated. are these techniques expected to produce Equally important, bombing accuracies from truly high resolution images, but they will high altitudes had not improved much since prove useful as a means of culling potential World War II, and were still often measured targets, reducing the number of tracks that in thousands of feet. At the same time, radar- need to be maintained before the target can guided SAMs were also eliminating the rela- be further classified using other means. tive sanctuary heretofore provided at these higher altitudes from ground-based air Weapons defenses. An operational crisis resulted, experienced by both the American and Israeli Air For obvious reasons, the appropriate weapon Forces in their wars of this period, in which for attacking a mobile target will depend on bombing effectiveness against both fixed and mobile targets was low, and even high alti- Hanoi. Post-Vietnam development of laser- tude operations faced serious opposition guided weapons was dominated by the fact from ground-based defenses. This crisis led that Europe, like Vietnam during the mon- to major investments in technologies for soon, usually had dense cloud cover, block- suppressing radar-guided SAMs, and for ing the use of LGBs from medium altitude, increasing the precision of weapons dropped and that Soviet radar-guided air defenses – from medium to high altitudes. whether mobile or fixed – were so dense Suppressing radar-guided SAMs would that there would be no sanctuary at medium reestablish a high altitude sanctuary from altitude.This led to the development of for- ground-based defenses, while precision ward looking infrared (FLIR) sensors that weapons would greatly increase the lethality would allow low altitude operation at night, and effectiveness of air operations from such putting the laser illuminator under the altitudes. SAM suppression came to depend weather and the aircraft under the radar on specialized aircraft known as Wild horizon, and also reducing to some degree Weasels, equipped with sophisticated, pas- the exposure to optically-guided short range sive, direction-finding avionics which could air defenses. But flying low and fast at night, identify and locate SAM radar emissions, and a fighter with a LANTIRN pod and LGBs armed with high speed, antiradiation missiles would still have had only modest capabilities (HARMs) which, once fired at an active to find its own mobile targets. This second radar, would either home on its emissions generation capability was not demonstrated and destroy it, or force it to shut down, caus- on a large scale until Desert Storm, where it 67 ing the SAM it was guiding to go ballistic was used from medium altitude against a and miss its target. The main method of totally suppressed air defense system against increasing the lethality of bombing opera- both fixed and mobile targets. tions was the development of the laser-guid- The wide deployment after Desert Storm ed bomb (LGB). Aircraft equipped with a of FLIR/laser illumination pods in both the laser illuminator could drop bombs from Air Force and the Navy greatly increased the high altitude that would home on laser percentage of the force with such energy reflected from the target.This great- night/clear weather precision strike capabil- ly increased the accuracy of bombing ities against fixed targets and mobile targets attacks, now measured in tens of feet, and with a clear IR contrast relative to their sur- also made accuracy relatively insensitive to roundings. But even over the deserts of Iraq altitude, allowing effective operation from and Kuwait, the need for clear weather the high altitude sanctuary established by the proved troublesome, and it proved crippling suppression of opposing radar-guided at times in the cloudy climate typical of SAMs. But this development did not address Serbia and Kosovo, a characteristic obtaining the problem of finding mobile targets from throughout the temperate zones of the medium and high altitudes and was relevant world, including the entire Asian littoral. mostly for attacks against fixed targets. The solution to this problem was First generation LGBs were day/clear weapons that integrate GPS and inertial weather systems, and were used only in the navigation systems (INS). Integrated latter part of Vietnam after the Air Force and GPS/INS provides a through the cloud, the Navy experienced repeated failure in weapon guidance capability that is compact, attacking high value fixed targets around relatively cheap, and which can be made robust against countermeasures. On the the other missiles, but carries a very small other hand, unlike LGBs, platforms carrying warhead. But like other air-launched rock- GPS-guided weapons are still generally ets, it too is currently too large to fit inter- unable to geolocate targets with their own nally on stealth fighters, and lacks the range sensors with the precision needed for an to be used by non-stealthy aircraft against organic, closed loop targeting system. GPS double digit SAMs. One element of the weapons have played a large role in both AARGM program is to develop a new Enduring and Iraqi Freedom, but when used motor for HARM which would increase against mobile targets the coordinates for both speed and range, while at the same time their targets were provided by other plat- allowing internal carriage. forms, often an individual on the ground Air-launched jet-propelled cruise missiles within line-of-sight to the target. like JASSM and SLAM are small enough to Weapons vary according to the range and be carried externally by non-stealthy fighters speed of their delivery.Standoff range is use- and can reach out to about 150-200 miles ful when opposing defenses are not sup- carrying 500 lb.warheads.But at those ranges, pressed, and speed of flight will determine which are necessary if the launch platforms the time lag between weapon launch and are not stealthy,flying subsonically at less than impact. GPS or laser-guided gravity bombs 10 miles a minute, the weapon takes at least have ranges of at most 10-15 miles, well 15-20 minutes to reach the target. within the range of most radar-guided air Cruise or ballistic missiles can also be 68 defense systems. Glide bombs like JSOW can launched from over the horizon by surface boost weapon range to about 40 miles, ships or submarines, or from friendly territo- which may be far enough to protect stealth ry. Standard 21” diameter and 20’ long aircraft from a SAM-10, but in that case they launchers can carry ballistic missiles that must be carried internally.This is not a prob- come in variants with ranges from 100-300 lem for B-2, but internal carriage becomes a miles and payloads varying from 1000 to 400 real constraint with aircraft like the F-22, lbs., or cruise missiles that can carry a 1000 lb. whose weapon bays are small. Hence the payload to a maximum range of 1000 miles. small diameter bomb program, which is a Weapons also vary in other respects. GPS-guided glide bomb with a maximum Gravity bombs like Paveway and JDAM cost range of 40 miles, a 250 lb. payload, and ter- as little as $20,000 apiece, whereas the other minal seeker.At 40 miles range, the time-to- weapons described above range in unit cost target for a glide bomb is at least 8 minutes. from $300,000 for the baseline JSOW Current rocket-propelled standoff wea- upward. In principal, any air-launched grav- pons like AGM-130 and 142 can deliver ity, glide, or rocket- propelled weapon could 500-1000 lb. payloads with less time-to-target be targeted by its launch platform, whereas over the same distance as a glide bomb, but beyond about 40 mile range, offboard target- these weapons are too large for internal car- ing usually becomes necessary. For targeting riage by any stealth aircraft, while at the same fixed targets or mobile targets at rest, time they do not provide enough standoff for weapons require either a laser spot to home non-stealthy aircraft to use them against tar- on, a precise GPS coordinate, an image of gets defended by double digit SAMs. the target and a terminal seeker with scene The HARM antiradiation missile is a matching capability,or a terminal seeker and special case in this category. It is faster than a data link back to the launcher that allows the launcher’s aircrew to do the scene the launch platform could generate these matching.Traditionally, weapons designed to templates but only in clear weather or under attack moving targets have used an optical the weather. Future scene matching weapons seeker with a tracker and have relied on the may retain their relatively simple, passive, pilot to designate the target and lock on the EO/IR seekers, but use scene matching seeker before launch. algorithms that allow target templates to be Future weapon developments will developed by either visible, IR, or SAR include new kinds of terminal seekers, images. For example, this would allow a smarter sub-munitions, and better scene strike fighter to use its SAR to target a cheap matching or target recognition algorithms. gravity or glide weapon through the weath- Today’s terminal seekers rely on scene er and in real time. matching and are usually passive, but future In addition to reducing the need for net- terminal seekers may use active millimeter works to produce precise target location wave or laser seekers more capable of recog- information, smarter sub-munitions and bet- nizing targets themselves, potentially elimi- ter scene matchers would also reduce the nating the need for a prior image of the current dependence on GPS for weapon target. Active seekers, if made small enough, guidance and possibly give weapons an equal can be used in smart sub-munitions which, capability against stationary or moving tar- if used against dense target arrays, could pro- gets. In both cases, INS systems would put duce multiple kills from a single weapon, and the weapon inside its terminal seeker’s basket, could also significantly reduce the demands with smart sub-munitions probably costing 69 on targeting networks, particularly in regard more, but also providing a much larger bas- to target geolocation accuracy. ket, whereas smarter scene matchers would At the same time, scene matching likely remain very cheap but also dependent weapons could also be improved. Today, the on their launch platform for a more accurate terminal seekers on scene matching weapons initial target location. Smart sub-munitions usually collect IR or visible light images and would be most compatible with standoff compare them to templates generated using weapons for use in higher threat environ- the same phenomenology. So an IR seeker ments, while smart scene matchers would be needs an IR image as a template, or an opti- most relevant when strike fighters have cal seeker needs an EO image. In principal, gained a medium altitude sanctuary.

Future strike fighter sensors will be both integrated and networked with other platforms. When ready for operational use, carrier-based UCAVS will provide unprecedented range and endurance to carrier strike groups which value those attributes highly. Conclusions

N CONCLUSION, one way to assess the future strike function in a single platform that can be of naval aviation is to look at its progression deployed on the smallest of naval combatants, Ito this point. For example, consider the fol- making the surface community air capable, lowing words, written sometime in May or and allowing the widest possible dispersion of June 1944 by Bernard Brodie, known then aircraft within the fleet. primarily for his work as a naval historian. Much about today’s aircraft has obviously changed, and much will change in the future, “The peculiar value of the airplane in but they will likely remain focused on recon- modern naval war extends over two naissance and strike broadly defined, both at very diverse fields – reconnaissance sea and ashore, where they will retain unique and attack. Almost every aerial bomb advantages in the altitude, speed, and maneu- that strikes home makes the front verability of their movements compared to page of the news, but the accomplish- platforms which are limited to maneuvering ments of the aerial observer are gen- in two dimensions. erally and understandably passed over Some of the changes to expect in the 71 in silence. Yet it may be doubted future have already begun, as in the develop- whether the reconnaissance value of ment and deployment of unmanned aircraft aircraft over the seas adds up to much to complement and perhaps eventually less than their attack value. The two replace manned aircraft. For the near to mid- cannot as a rule be separated, but term, it appears that this trend will be most great decisions have been made and pronounced in those applications where large operations put in progress on range, endurance and in some cases, altitude the basis of intelligence gained from are the most valued attributes. By compari- the air. Correct intelligence is the son, manned aircraft will likely remain above least publicized but also the most ele- the battlefield for the foreseeable future in mental prerequisite of successful war- those applications where disparate, often fare.”xvii ambiguous, sensor inputs must be quickly fuzed, assessed, and acted upon quickly and One can see in these words the genesis of decisively in order to achieve the desired tac- today’s carrier-based strike fighters and land- tical outcome. based maritime patrol aircraft (as well as the The most important and perhaps misun- long history of greater public attention to the derstood change which is unfolding lies, on former over the latter). One can also see by the one hand, in the increasing benefits that comparison to today one of the main changes will flow from networking the sensors from in the structure of naval aviation that multiple aircraft toward a common purpose, occurred in the intervening years – the emer- and on the other in the concomitant poten- gence of the multi-mission helicopter. tial that the network itself will become a new Helicopters combined the reconnaissance and source of vulnerability, either through the insecurity of its links, or the indispensability sensors, weapons, and decision makers be of one of its nodes. The potential benefits to collocated on the same platforms. be derived from networking are overwhelm- Another set of conclusions concerns like- ing, as are those associated with unmanned ly future sensor capabilities in different envi- platforms, but much discussion to this point ronments. Four distinct environments are is characterized by less focus on the poten- important: air (and space), sea surface, land, tial vulnerabilities and constraints. and undersea. Variations in terrain (or For example, many advocates of “net- hydrography) will have significant effects in centric warfare” possess a near mystical belief some environments (land and undersea) by in both the power and future availability of reducing detection ranges. Variations in bandwidth at radio frequencies on and over weather will be important wherever optical future battlefields. Certainly, much band- (as opposed to radar) sensors play an impor- width there already is, and more there will tant role on the battlefield. Clutter, when it be, but all RF bandwidth used for commu- exists, will greatly complicate the ability of nication or data relay purposes can be opti- sensors to identify moving targets ashore and mized either to maximize data rates or fixed targets undersea. minimize vulnerabilities to detection and For these and other reasons, conclusions jamming but not both. Today, many of the about future sensor capabilities for use best examples of net-centricity that have against airborne and space-based platforms, been demonstrated depend on links with or against fixed land targets should vary con- 72 very high data rates. Networks dependent siderably from the capabilities for use against on such links would not be viable on many mobile land targets or stationary or slow future battlefields, requiring that their nodes moving undersea targets. In the former retain some capability for autonomous oper- cases, detection ranges are relatively long and ation. But network designers anxious to classification is often straightforward, where- reap the maximum benefits from a net- as in the latter cases, detection ranges are worked force, and infused with the assump- almost always much shorter and classification tion of infinite bandwidth, will be tempted much more difficult. In the former cases, to design network nodes that can not func- radar is dominant, whereas in the latter cases tion autonomously. a high degree of multi-spectral sensor fusion These issues speak both to the question of is often necessary. whether to man airborne platforms or not, As important as these largely technical and whether to deploy multi-sensor plat- trends will be a series of political and doctri- forms on which some degree of sensor nal trends. The most important political fusion occurs onboard or to deploy highly trend is the reduction in reliable and pre- specialized single sensor platforms whose dictable access to overseas bases that accom- output can only be fuzed with other sensors panies the reduction in salience of formal using a network. In the case of reconnais- alliances as compared to more informal sance and surveillance aircraft, the trends coalitions. This trend is based on a basic toward unmanned operation and network structural change in the external security dependence can and should be more pro- environment and is therefore likely to last for nounced than with strike aircraft, where the foreseeable future. It is the main reason both the operating environment and the why sea basing has grown in such relative nature of the mission will often require that importance in both major combat operations such as Enduring Freedom and Iraqi The need for a dominant defense of the Freedom, and in operations against global sea base in the cluttered littoral environment terror networks which often incubate and splits into two primary challenges: the chal- metastasize in exactly those regions of the lenge of recovering detection, classification, world where one wouldn’t want access to and engagement ranges against cruise missiles bases ashore even if it was available. and their launchers operating ashore, on the At the doctrinal level, the most important sea surface, and in some cases undersea; and trends for naval aviation are the evolution the challenge of adapting to the inherently toward distributed air-ground operations reduced detection, classification, and engage- ashore, and toward the need for a dominant ment ranges against submarines (and mines). defense of the sea base in a littoral as As this report shows, naval aviation is pro- opposed to a blue water environment. The gressing toward solutions to each of these former creates the demand for a persistent challenges. Success in these areas will in turn and distributed air force capable both of pre- enable the full exploitation of the sea base’s venting major concentrations and move- capabilities to influence and control events ments of enemy forces on the ground, both on the high seas and ashore, against the enabling the use of smaller and lighter full spectrum of threats. It is necessary to friendly ground units, and of rapidly and sustain this progress in the coming years and precisely supporting friendly forces when decades because the future security environ- they encounter and engage smaller pockets ment will brook no alternative solutions to of enemy resistance that cannot be detected the major security challenges faced by the 73 and attacked from afar. United States. Notes

i Conduct of the Persian Gulf War (Washington, D.C.: U.S. Department of Defense,April 1992), p. 35. ii Peter Grier,“Pentagon Speeds Forces to Hot Spots,” Christian Science Monitor, October 18, 1994, p. 1. iii Douglas Jehl,“Saudis Admit Restricting U.S.Warplanes in Iraq,” New York Times, March 22, 1999, p. 6. iv The U.S. Commission on National Security, New World Coming (Washington, D.C.August 1999) p. 7 . v Report of the National Defense Panel, December 1997, pp. 12–13 . vi On the United States being an offshore balancer of last resort, see Christopher Layne,“From Preponderance to Offshore Balancing:America’s Future Grand Strategy,” International Security,Vol. 22, No. 1 (Summer 1997), pp. 112–123. I am predicting that the United States will adopt that broad role for reasons quite different from those proposed by Layne, but his description of how such strategy might work in practice is useful. On Britain’s historic role as an off shore balancer in Europe, see Daniel A. Baugh,“British Strategy during the First World War in the Context of Four Centuries: Blue-Water versus Continental Commitment,” in Daniel Masterson, ed., Naval History: The Sixth Symposium of the U.S. Naval Academy (Wilmington, Del.: Scholarly Resources Inc., 1987), pp. 85–110. vii At about 500-600 km range, missile designers must start considering staging if they wish to pre 74 serve a reasonable payload.Though a two stage TBM is far from infeasible, it is a leap ahead in both technology and cost, and given the simplicity of the cruise missile alternative, the latter may be preferred. viii For an excellent discussion of such TBMs and cruise missiles, from which this discussion of the vulnerability of fixed targets draws liberally, see John Stillion and David T. Orletsky,Airbase Vulnerability to Conventional Cruise-Missile and Ballistic-Missile Attacks:Technology, Scenarios, and U.S.Air Force Responses (Santa Monica, CA.: Project Air Force, RAND, 1999). ix Again, in the long run, the U.S. Navy’s recent decision to give its next surface combatant electric drive may prove fortuitous if this provides the power supply for terminal, directed energy defenses using solid state or free electron lasers if and when the latter become feasible.A surface ship is the perfect candidate for such a terminal defense because it is continuously moving, which means it can only be attacked by weapons with terminal seekers that a laser can burn.At the same time, it is among the largest and highest value moving targets, which means that unlike ground vehicles it has a large, organic supply of power which, on an electric drive ship, can be rapidly turned into electricity to power a laser. x These are all points made by Stillion and Orletsky,Airbase Vulnerability, p. 31. xi Edward N. Luttwak,‘The Operational Level of War,” in Strategy and History: Collected Essays,Vol. 2 (Transaction Books, New Brunswick, N.J.: 1985) pp. 182-186. xii For a summary of this debate, see Harvey M. Sapolsky and Jeremy Shapiro,“Casualties,Technology, and America’s Future Wars,” Parameters,Vol. XXVI, No. 2 (Summer 1996) pp.119-127. xiii The best account of those events is Mark Bowden’s masterful Black Hawk Down:A Story of Modern War (New York:Atlantic Monthly Press, 1999). xiv Stephen Walt,“Muscle-bound:The Limits of U.S. Power,” Bulletin of Atomic Scientists, March April 1999, p.44. xv Douglas Barrie,“India Begins To Receive Russian Missiles for Subs,” Defense News, October 23, 2000, p. 60. xvi For a vivid description of these early LGB operations, see Jeffrey Ethell and Alfred Price, One Day In A Long War (New York: Random House, 1989). xvii Bernard Brodie, A Guide to Naval Strategy, Third Edition (Princeton, N.J.: Princeton University Press, 1944) pp. 211-212.

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