ORG Explains #6 Sustainable Security Programme UK-US Defence and Security Relations Richard Reeve – July 2018 Subject: Key points: This primer explains the legal and institutional • The UK and US are bound together legally basis of current defence and security relations by the multilateral NATO Charter and a between the United Kingdom and the United series of bilateral agreements over States, including cooperation on nuclear exchange of intelligence and technology. weapons, intelligence-sharing, conventional • Cooperation between the UK and US on forces and weapons development and nuclear weapons development, procurement. manufacture and testing is unprecedented Context: and may breach Non-Proliferation Treaty (NPT) obligations. The “special relationship” between the United • Intelligence-sharing is probably the closest Kingdom and the United States is often institutional relationship and provides the referenced by politicians but the reality behind US with access to a global network of mass the rhetoric is little understood. While the surveillance facilities in the UK and British warmth of personal relationships between Overseas Territories. prime ministers and presidents may wax and wane, a series of complex and often opaque • The US military also uses several air and institutional relationships and infrastructure naval bases in the UK and overseas bind the two countries’ defence and security territories, notably for supporting nuclear- sectors more closely together than to any capable strategic bombers and submarines. other partners. The UK is likely to remain the • British desire to be a “full-spectrum” US’ most capable and valued military and military partner to the US at least partially intelligence ally for some time to come, but the determines the structure of UK forces, relationship is inherently asymmetric given including a deployable Army division, that Washington deploys resources around ten aircraft carriers and nuclear weapons. times larger than London’s. This has very • The UK is the US’ closest military industrial significant impact on the independence of the and scientific partner, not least in the F-35 UK’s conventional and nuclear military forces Joint Strike Fighter project. While the as well as its involvement in global mass British military is increasingly reliant on surveillance operations. As with the economic imports from the US, British industry and legal relationship between the UK and the partners at least as much with European as European Union, unravelling the defence and with US peers. security relationship with the United States would likely be complex and expensive. 1 What is the legal basis of UK-US defence and contrary to the Nuclear Non-Proliferation security relations? Treaty (NPT), in force since 1970. Despite enjoying what the UK Ministry of The Polaris Sales Agreement (1963) is the Defence calls “the broadest, deepest and most other pillar of UK-US nuclear cooperation. It advanced [defence and security relationship] secured the supply to the UK of submarine- of any two countries”, the United Kingdom and launched Polaris missiles, including launch United States have no bilateral defence treaty. tubes and guidance system. The agreement Instead, the legal basis of their relations is the was updated in 1982 to cover the next multilateral NATO Charter and a series of generation Trident missile system and remains agreements relating more specifically to in force. intelligence and nuclear capabilities sharing. The Defence Trade Co-operation Treaty The British-US Communication Intelligence (2007) removes the need for specific Agreement (known as UKUSA, 1946) is the authorisation of many defence equipment secret (until 2010) agreement governing sales between the two countries and allows intelligence-sharing between the UK and US the transfer of certain sensitive technologies to plus Canada (1948), Australia and New Zealand facilitate the joint development of new (both 1956). This alliance is commonly known weapons. This seems to have been motivated as Five Eyes and comprises by far the world’s by the British need for rapid delivery of largest network for gathering and sharing equipment for use in coalition operations in electronic and signals intelligence from posts in Iraq and Afghanistan as well as the needs of the the five members and their overseas US-led F-35 Joint Strike Fighter programme for territories. This mass surveillance network is trans-Atlantic cooperation. Only Australia also known as ECHELON. has such an arrangement with the US. The North Atlantic Treaty (1949) is the legal basis for UK-US mutual defence obligations What are the priority areas for UK-US within NATO. This prescribes the geographical defence and security cooperation? area of mutual defence as Europe, the While the UK and US cooperate on virtually Mediterranean, the North Atlantic and North every element of their defence and security America. It thus does not bind the UK to defend policies, the key areas are intelligence Hawaii or US territories in the Pacific; nor does collection and sharing, nuclear weapons, naval it bind the US to defend British Overseas and special forces. Territories other than Gibraltar, Cyprus bases and Bermuda. The greatest value to the US from the relationship would seem to be British The so-called Mutual Defence Agreement capabilities for intelligence collection, (1958) is not a mutual defence treaty but an including strategically positioned electronic agreement permitting the US and UK to share listening posts on British Overseas Territories critical information and materiel required for in the Mediterranean, Indian and South the manufacture of nuclear weapons and Atlantic Oceans. While the US is very much the delivery systems. This has included nuclear dominant partner in Five Eyes, it relies heavily propulsion systems for submarines and on British inputs. Similarly, mainland Britain is plutonium. The critical article of the an important node relaying military and Agreement (III bis) is revised and renewed intelligence communications between the US every 10 years. No other two nuclear weapons and Europe, Africa and the Middle East. The states have such an agreement and it is key relationship is between the US National debatable whether the transfer of nuclear weapons technologies and materials is not 2 Security Agency (NSA) and the UK Government terms of naval forces and special forces. All UK Communications Headquarters (GCHQ). armed forces are designed and trained to be interoperable with US forces. Perhaps the greatest value to the UK from the relationship derives from US technical The priority for US-UK naval cooperation is assistance to its nuclear weapons programme. bringing the two new British aircraft carriers Thus, the US covers most of the development and their F-35B airwings into operation. While costs of the Trident intercontinental ballistic the UK has designed and built its own carriers, missile (ICBM), while the UK designs its own it is dependent on US support to develop, build ballistic missile submarines (around the US- and bring the aircraft into service. Thus, British built common missile compartment) and F-35B pilots train in the US and the carriers will, nuclear warheads. The 2014 renewal of the for at least their first few years, operate mixed Mutual Defence Agreement also appeared to squadrons of UK and US Marine Corps F-35B. include revision to allow the US to supply The deployment of Royal Navy carrier strike technology needed by the UK to develop a groups will be coordinated with deployment of nuclear propulsion system for its new US carriers and likely include at least one US Dreadnought class submarines. While the UK Navy destroyer. probably has the technical capacity to follow The other big area of naval cooperation is France in developing its own ICBMs and all operations to control sea lanes , not least aspects of its nuclear submarines, this would those on key oil-supply routes, such as the Red entail an additional cost of billions of pounds. Sea-Gulf of Aden-Arabian Sea-Persian Gulf. The US gains by recovering a less significant There, the two countries command (US) and share of its development costs via British deputy command (UK) multinational participation. It may feel it benefits more from Combined Task Forces from their adjacent HQs the political dimension of a closely coordinated in Bahrain. Similar imperatives drive the US nuclear alliance, for example in its approach to desire for the Royal Navy (and others) to revive international nuclear disarmament initiatives. its presence in the South China Sea, where China has established air and naval bases. Contrary to some accounts, the US is unlikely to be able to prevent the UK from launching its UK and US nuclear attack submarines also have Trident missiles, nor to over-ride their a unique ability to work together in anti- guidance in-flight. However, it is difficult to submarine warfare tasks under the Arctic imagine the UK using its nuclear weapons icecap. Such cooperation has been revived without coordination with Washington. since 2016 in response to Russian activity and greater cooperation (with Norway) is planned The other important dimension of strategic as the RAF brings its new P-8A aircraft into weapons in the relationship is the designated service from 2019. use of British air bases in the UK and Diego Garcia atoll by the US Air Force (USAF) for Land forces cooperation may be of lesser forward deploying nuclear bombers. No other importance at present. While the MoD appears country currently provides such basing, to base its Army structure at least partly on the although several European countries do host desire to contribute a division-sized formation US tactical nuclear weapons and strike aircraft. (15,000+ personnel) to coalition operations, as The UK is also able to support US nuclear- it did in both Iraq wars, its actual capacity to do armed submarines in Scotland if necessary. this is now widely doubted. Moreover, the US itself has deprioritised the kind of major land Conventional military forces are of lesser offensives that might require such significance in the relationship but there is a reinforcement.