the years immediately following World War II, the United States was the only nation with the atomic bomb. Its strategic dominance, however, rested on a thin veneer of actual military capability. As late as 1947, the US did not have any atomic bombs assembled and ready for use. The Atomic Energy Commission, which held custody, was to work up the bombs and transfer them to the Air Force if and when they were needed. The Air Force had only a few airplanes, “Silver Plate” B-29s, that could deliver the bomb, and few trained crews. The leading atomic scientists who developed the atomic bomb during the war had left the Los Alamos weapons laboratory in New Mexico. Most of them were opposed to further military development of atomic energy. The US in 1946 proposed international control of atomic weapons. The offer to the United Nations fell through because the Soviets demanded the US eliminate its nuclear weapons as a precondition to agreement.

J. Robert Oppenheimer and his colleagues opposed development of the hydrogen bomb.

The fi rst thermonuclear explosion was the “Ivy Mike” test at Eniwetok Atoll in the Pacifi c in 1952. The fi reball was three miles wide and vaporized the coral islet on which the shot occurred.

62 AIR FORCE Magazine / October 2015 The concept for a far more powerful nuclear weapon—the hydrogen bomb, called the “Super” by the atomic scientists—had been around for some time. Few outside of the scientific community knew about it, and except for a few scattered advocates, there was almost no inter- est in pursuing it. Until October 1949, the President of the United States had never heard of the hydrogen bomb, nor had the Joint Chiefs of Staff. Disclosure beyond the scientific inner circle was brought about by dramatic events and a few determined insiders. The Soviet Union exploded a nuclear device, “Joe 1,” Aug. 29, 1949. It was an exact copy of the “Fat Man” atomic bomb dropped on Nagasaki, Japan. Brit- ish scientist Klaus Fuchs, arrested in London, admitted in January 1950 that he had passed atomic secrets, stolen at Los Alamos, to the Soviet Union.

By John T. Correll

AIR FORCE Magazine / October 2015 63 President Truman, informed that a Edward Teller, the foremost advocate hydrogen bomb was possible and ad- of the hydrogen bomb, could not get vised that the Soviets might not be that his “Classical Super” to work. Deto- nation of a thermonuclear device, it far behind, ordered a development pro- was subsequently learned, required gram into high gear. The United States compression of the fission fuel, not did not yet know that the Soviet Union just high levels of heat. had been working on a hydrogen bomb since 1948, aided by research obtained would use atomic energy for peaceful by espionage from Los Alamos. purposes. It might have been accepted if the Soviet Union had not refused A EA E to concede veto power in the UN on An atomic or fission bomb is ex- atomic issues. The international control ploded by bringing enhanced uranium or issue bubbled along into 1948, but it plutonium to critical mass. A hydrogen was essentially over. or fusion bomb is a two-stage device. Oppenheimer wrote and spoke often The primary stage is an atomic bomb, in favor of international handling of which acts as a trigger, aided by another atomic energy and open communication atomic “spark plug” in the secondary on science. “We vastly overestimate the stage, to compress and ignite hydrogen value of secrecy and underestimate the isotopes. The thermonuclear chain reac- corrosive effects of it,” he said. tion thus induced releases 1,000 times The Atomic Energy Act of 1946 more energy than an atomic bomb. transferred control and custody of The Manhattan Project team at Los nuclear weapons from the military to Alamos was aware of the theory that an the new Atomic Energy Commission. atomic bomb might be able to detonate The first AEC chairman was David E. a fusion explosion. However, with time Lilienthal, an ardent New Dealer, head re ce er ore t o bor tor oto pressures of the war bearing down on of the Tennessee Valley Authority, and them, they chose to concentrate on an implacable foe of the Super, which he the fundamental task of producing an regarded as dangerous and unnecessary. atomic bomb, a formidable challenge Most of the AEC commissioners in itself. sided with Lilienthal. The exception Physicist Edward Teller, the foremost was Lewis Strauss, a former investment advocate of the Super, was permitted to banker, a rear admiral in the Navy Re- conduct theoretical fusion research as serve, and a hard-nosed Cold Warrior. a minor effort at Los Alamos, but lab He, along with Teller, Oppenheimer, director J. Robert Oppenheimer kept and Lilienthal would figure prominently the project’s emphasis on the atomic in the melodrama to come. bomb, which was tested successfully The armed forces were not particu- in July 1945. The clash between Teller larly worried about nuclear weapons. and Oppenheimer would continue spec- Military intelligence did not expect a tacularly over the next 10 years. challenge to the US monopoly. The When World War II ended, the United Navy predicted the Soviets would not States felt secure in its military superi- have the bomb until 1965. The Army ority and had no inclination to develop guessed 1960; the Air Force said by more powerful weapons—or to take an 1952. adversarial position toward its wartime In January 1949, the AEC nuclear ally, the Soviet Union. stockpile reached 56 atomic bombs. In his famous speech at Westminster College in Fulton, Mo., in March 1946, R MA ECI IO Winston Churchill warned that an “Iron The Soviet atomic bomb test in Curtain” had descended on Europe. It August 1949 was discovered soon is seldom remembered that the speech thereafter by the United States and was poorly received at the time. The announced to the world by President New York Times reported that President Truman on Sept. 23. The surprise set Truman had no comment and the pre- off renewed interest in the hydrogen vailing opinion in Congress and “in the bomb by the AEC and in Congress by high councils of the Administration” the Joint Committee on Atomic Energy. e rt e t o er oto was that Churchill had been excessively At an AEC meeting Oct. 5, Strauss J. Robert Oppenheimer, who led the develop- provocative toward the Soviet Union. distributed a memo to his fellow com- ment of the atomic bomb, was opposed to the In June 1946, the United States missioners proposing a “quantum jump” hydrogen bomb. He was stripped of his secu- offered to give up its store of atomic in nuclear capability and “an intensive rity clearance by the AEC in 1954 because of his continued association with Communists weapons and turn its atomic secrets effort to get ahead with the Super.” and a casual attitude toward information over to a proposed UN International It was the first clear proposal for the security—although animosity from those who Atomic Development Authority, which hydrogen bomb. disliked him likely played a part as well. AIR FORCE Magazine / October 2015 that had stolen atomic secrets from Los Alamos during the war.

E E I A OR E Edward Teller struggled through the postwar years but could not get his de- sign for the “Classical Super” to work. He assumed, erroneously, that the heat from an atomic device alone would be enough to ignite fusion. In 1950, mathematician Stanislaw Ulam, using new high speed computers, discovered a mistake made by Teller and his associates in 1946. Direct ignition would take an impractical amount of tritium, one of the hydrogen isotopes in the fission fuel, if it would work at all. Ulam said Teller “was not easily reconciled” to the report of the error but “warmed” to the idea of a “staged” ap- proach when Ulam suggested it in January 1951. In March, Teller and Ulam wrote a classified paper on a new concept, in which an atomic bomb might ignite a secondary explosion in fission fuel located t o rc e ecor tr t o oto separately from the atomic trigger in the President Eisenhower takes a briefing from Lewis Strauss, AEC chairman, on the hydrogen bomb casing. hydrogen bomb tests in 1954. Strauss distrusted Oppenheimer. Detonation of the thermonuclear fuel would require compression as well as Strauss then met with the executive to give the highest priority to H-bomb heat. Teller improved the idea by adding secretary of the National Security development. The Joint Chiefs of Staff a second atomic component as a “spark Council and instigated the first notice agreed with Strauss. Truman sought plug” in the second stage of the process. to Truman of the possibility of a hy- further advice from a special commit- Thus, embedded within the hydrogen drogen bomb. The Joint Chiefs of Staff tee consisting of Lilienthal, Secretary bomb were the atomic bomb trigger were let in on the secret the following of State Dean Acheson, and Secretary and the atomic spark plug in a separate week. It became public knowledge in of Defense Louis A. Johnson. Acheson cylinder. November when Sen. Edwin C. Johnson and Johnson advised Truman to proceed The revised configuration was ultimate- (D-Colo.) revealed on a local television with the Super. ly successful, but to Teller’s displeasure, broadcast in New York that American Speculation in the press was in- it was called the “Teller-Ulam design.” scientists were trying to make a “super flamed by the news from Britain that Teller resented Ulam’s contribution be- bomb” many times more powerful than physicist Fuchs had confessed to ing accorded equal credit with his own the atomic bomb. passing atomic and hydrogen secrets previous 10 years of work and said that AEC chairman Lilienthal responded to the Soviet Union. Fuchs had been the final configuration had been his. by calling in the Commission’s Gen- a British representative at Los Alamos Nevertheless, the Teller-Ulam designation eral Advisory Committee, which was and had seen all of the research in stuck and went on to be used in almost chaired by Oppenheimer. The commit- the archives there on thermonuclear all modern nuclear weapons by all of the tee members were atomic scientists weapon research. major nuclear powers. stridently against a hydrogen bomb. Truman made his decision Jan. 31, After a two-day meeting, they produced 1950. He asked Acheson, Johnson, and I MI E a report on Oct. 30 saying that all-out Lilienthal whether the Soviets could The first successful explosion of a development of the hydrogen bomb develop a hydrogen bomb. They agreed hydrogen device was the “Ivy Mike” test would be “wrong.” that the Soviets probably could. “In that Nov. 1, 1952, in the Marshall Islands, a In remarkably harsh language, Op- case, we have no choice,” Truman said. remote section of the Pacific about 1,200 penheimer and the GAC said that “a “We’ll go ahead.” miles east of Guam. The device weighed super bomb might become a weapon of Congress gave Truman overwhelm- 82 tons and was essentially more a build- genocide,” represented “a threat to the ing approval, across party lines, for ing than a bomb. It was constructed on future of the human race,” and that “a his decision, but the atomic scientists Elugelab, one of 40 coral islets in the super bomb should never be produced.” and many in the news media disagreed Eniwetok Atoll. In the opinion of the GAC, “the extreme vehemently. Lilienthal resigned, as he After the war, the United States had des- dangers to mankind inherent in the pro- had planned to do anyway. ignated Eniwetok, along with the Bikini posal outweigh any military advantage Truman’s decision gained additional Atoll, for testing of nuclear weapons and that could come from this development.” credibility that summer when the FBI the native inhabitants had been relocated. By that time, Truman had heard arrested Julius and Ethel Rosenberg Observers watched the Ivy Mike test from directly from Strauss, who urged him and other members of a Soviet spy ring various islands a safe distance away. AIR FORCE Magazine / October 2015 Ivy Mike detonated with a ther- a hydrogen installation.” The United judgment and veracity with confl icting monuclear yield of 10.4 megatons, a States dropped its fi rst H-bomb from accounts in 1943 and 1946 of his deal- thousand times more powerful than an airplane in May 1956. ings with Hakkon Chevalier, a friend the “Little Boy” bomb at Hiroshima, and fellow member of the faculty at and vaporized Elugelab. “Once the OUSTING OPPENHEIMER Berkeley. In 1943, Chevalier tried to explosion broke through the casing, it Strauss became director of the AEC recruit Oppenheimer to provide tech- expanded in seconds to a blinding white in July 1953. The stage was set for the nical information to the Soviet Union. fi reball more than three miles across fi nal showdown with Oppenheimer, who Oppenheimer delayed for months tell- (the Hiroshima fi reball had measured was regarded by many in the AEC and ing Manhattan Project security about it little more than one-tenth of a mile) the Pentagon as a security risk. and then said the approach was by an and rose over the horizon like a dark By then, Oppenheimer was director unknown stranger. He later acknowl- sun,” said Richard Rhodes, author of of the Institute for Advanced Study in edged to the FBI that the Soviet agent Dark Sun: The Making of the Hydrogen Princeton, N.J., and no longer on the had been Chevalier. Bomb. “The crews of the task force, 30 GAC but he was a consultant under Oppenheimer’s pattern of conduct miles away, felt a swell of heat as if contract to the AEC. In that capacity, led Air Force leaders in 1951 to order someone had opened a hot oven, heat he routinely got copies of classifi ed that he not be used as a consultant or that persisted long enough to seem reports from all AEC divisions. His given classifi ed information. Strauss menacing.” consultancy was to expire in 1954 and had deeper doubts and thought Op- The fi rst thermonuclear test by the his security clearance had to be renewed penheimer might be “another Fuchs.” Soviets, “Joe 4,” came less than a year if the contract was to be extended. In November 1953, a former staff later. They evacuated tens of thousands The question of his security clearance director of the Joint Congressional of people from Semipalatinsk in north- was not strictly a matter of loyalty. It Committee on Atomic Energy wrote eastern Kazakhstan, mounted a bomb also had to do with his casual attitude to the FBI saying that Oppenheimer the size of the US “Fat Man” atomic toward information security, an issue was not trustworthy. bomb atop a tower, and touched it off on which he and Strauss had tangled With these allegations swirling about for a modest yield of 400 kilotons in before. Oppenheimer’s continued as- in 1953, Oppenheimer made the situa- August 1953. sociation with known Communists was tion infi nitely worse by visiting his old More tests followed on both sides. also a concern. friend Chevalier in Paris and going to The highest yield ever achieved by Some of it was old news. Oppen- dinner with him. To Oppenheimer’s a US device, 15 megatons, was the heimer’s wife and brother had been mind, Chevalier’s politics were harm- “Castle Bravo” shot at Bikini in March members of the Communist Party in the less, but US offi cials were enraged. 1954. The fi reball was nearly four 1930s. Oppenheimer described himself President Eisenhower cut off Oppen- miles wide. The Soviets dropped a 1.6 as a “fellow traveler” who contributed heimer’s access to atomic secrets and megaton bomb from a Tu-16 bomber money to Communist causes until the AEC suspended his clearance in in November 1955. 1942. His qualifi cations to be scientifi c December 1953. Soviet leader Nikita Khrushchev director of the Manhattan Project had A special AEC Personnel Security gloated that his nation had been fi rst overridden concerns about his previous Board held hearings, taking testimony to explode a hydrogen bomb from an activities. from Oppenheimer and others over a airplane. The previous US explosion, After that, however, Oppenheimer period of two months. Among those he said, “was not a hydrogen bomb but generated new questions about his testifying was Edward Teller, who

Truman, shown here on a tour of Andrews Field, Md., with Air Force escorts, had never heard of a hy- drogen bomb until October 1949. He decided that the United States had “no choice” except to proceed with development.

66 AIR FORCE Magazine / October 2015 said Oppenheimer had continually used his influence to slow down work on the hydrogen bomb. Teller did not Photo USAF accuse Oppenheimer of disloyalty but said he “would feel personally more secure if public matters would rest in other hands.” In May 1954, the Personnel Security Board recommended against the rein- statement of Oppenheimer’s clearance. Oppenheimer appealed to the full AEC, which concurred in June with stripping him of his clearance. Oppenheimer, who had gotten fa- vorable press throughout his ordeal, won the battle for public opinion. The standard interpretation is that he was unfairly ousted by vindictive enemies on the political right. For the rest of his life, Oppenheimer was a cult figure and something of a folk hero. Strauss The B53 thermonuclear bomb display at the National Museum of the US Air Force and Teller became pariahs. in Dayton, Ohio.

THE HYDROGEN ERA carried around the world by upper air other than an imputed psychological Strictly speaking, the “Atomic currents. There was not enough fallout effect that might to some extent restrain Age”—much heralded at the time—did from atomic bombs to make it a major an adversary. The point was correct but not last long. Ten years after the first problem, but hydrogen bombs, with that imputed effect—known as deter- atomic test in the New Mexico desert fireballs four miles wide, scooped up rence—kept the nuclear peace until the in 1945, the atomic bomb had been all massive amounts of dirt, sand, and dust. Cold War ended some 40 years later. but superseded by the hydrogen bomb. As the AEC explained it to the The terms “atomic bomb” and “hy- The armed forces, which had been newspapers, fallout from a hydrogen drogen bomb” are seldom used today, shut out of nuclear affairs by the AEC, bomb explosion over Washington, D.C., except in a historical context. The stan- gained a stronger hand. On several oc- would reach almost to New York and be dard reference is to “nuclear weapons,” casions, President Truman transferred a potentially lethal to the entire popula- without differentiation between fission number of complete bombs to military tion within the first 140 miles. This led and fusion devices. control although AEC and the State to the civil defense boom of the 1950s Almost all of the nuclear weapons Department convinced him not to make and 1960s, with many families building in the hands of the major powers at it a regular policy. In 1956, Eisen- fallout shelters in the backyard. present are of thermonuclear design hower gave the Defense Department The Super became an issue in the because it is more efficient. Thermo- custody of nuclear weapons whenever 1956 presidential election with Eisen- nuclear bombs, of course, use atomic an emergency was declared, and in hower’s Democratic challenger Adlai bombs as triggers for detonation, just 1959 released all operational bombs Stevenson proposing that the United as Ivy Mike did. and warheads outright to the military. States stop further tests of the hydrogen The British tested a thermonuclear Advancing technology made hydro- bomb. He said the Soviet Union would device in 1958, followed by China in gen bombs smaller and more powerful, be willing to join in such a policy. His 1967, France in 1968, and India in leading to warheads that were light running mate, Sen. Estes Kefauver 1998. Israel is presumed to have the enough to be delivered by an ICBM (D-Tenn.), said it was “general infor- hydrogen bomb. as well as an airplane. Eventually, the mation” that a hydrogen bomb could Pakistan has not tested a thermo- Mark 12-A thermonuclear warhead “blow the Earth off its axis by 16 nuclear device, but could probably do used on Minuteman missiles would be degrees.” According to The New York so with a determined effort. less than six feet long and weigh about Times, “responsible scientists” found In 2014, North Korea said its scien- 700 pounds. Kefauver’s claim “incredible.” tists had achieved nuclear fusion, but A casing of the Mark 53 hydrogen Eisenhower, who said the Steven- the claim was generally discounted. bomb, deemed “an enduring symbol son’s plan was “pie-in-the-sky promises For some years, the United States of the Cold War,” is on display at the and wishful thinking,” won the Novem- continued to deploy atomic weapons National Museum of the US Air Force in ber election by a landslide. for tactical use, but the last atomic Dayton, Ohio. It weighed 9,000 pounds, Khrushchev, in his customary fash- bomb in the US inventory, the B57, generated a yield of nine megatons, and ion, said the USSR would soon “have was removed from service in 1993. J was carried by B-47, B-52, and B-58 a guided missile with a hydrogen bomb bombers. The Titan ICBM delivered a that can fall anywhere in the world.” John T. Correll was editor in chief of Air modified version. Force Magazine for 18 years and is now The public learned a new word: fall- LEGACY OF THE SUPER a contributor. His most recent article, out, referring to radioactive particles Critics of the hydrogen bomb in the “Opposing AWACS,” appeared in the gathered up by a nuclear explosion and 1950s said that it had no military value September issue. AIR FORCE Magazine / October 2015 67