Dark Sun: The Making Of The Hydrogen Bomb

The same day he sent this will-o'-the-wisp message, which made headlines across America when Forrestal reported it in congressional testimony on March 8, Clay wrote a senator that American personnel were “as secure here [in Berlin] as they would be at home… ” Clay told a biographer long afterward that he sent his war-scare cable because the Army's director of intelligence had come to see him in Berlin in late February and told him “that the Army was having trouble getting the draft reinstated, and they needed a strong message from me that they could use in congressional testimony.” In the upshot, Marshall got his aid and the aviation industry was rescued. With the Truman administration worried about inflation, the military fared less well.

In the meantime, on March 17, Britain, France and the Benelux countries committed themselves to alliance in the Treaty of Brussels. Then it was the United States's turn to begin negotiating a military alliance with Britain and Canada, writes the British diplomat Robert Cecil, who attended the first secret meetings:

Bevin judged that the time had come to propose to the State Department that the US government, having already decided to invest in Western Europe's recovery through the Marshall Plan, should agree to undertake the defence of its investment, if this should prove necessary. It was essential, however, to proceed with caution, since Republicans dominated Congress and Congress had never sanctioned a military alliance in time of peace. On 22nd March, with no fanfare and no accompanying staff, Sir Gladwyn Jebb (Lord Gladwyn) came out from London and Lester Pearson from Ottawa. The State Department, fearing that their joint arrival on their doorstep with delegations drawn from their Embassies might provoke press enquiries, decided to hold the initial meetings at the Pentagon, which in those days was less haunted by the press corps. Further to discourage premature leakage, it was stipulated at the opening meeting that no notes should be taken and that we should not disperse for lunch, which was eaten at the long table where discussion took place.

The meetings continued through April 1. The US had rejected inviting the French because the State Department feared they might compromise security, but Cecil's senior partner at the negotiations was Donald Maclean. Maclean certainly communicated the substance of the discussions to the MGB. The Polish newspaper Zycie Warszavy published an article on a North Atlantic alliance on April 4 that described the secret Anglo-American plans; a British Foreign Office internal memorandum noted at the time that the article “did sail pretty near the wind.” The secret discussions included an agreement among the parties to aid each other militarily in the event of an armed attack; Canada tabled a proposal that “among others, Western Germany and Western Austria might join” the alliance. The possibility that the West might rearm Germany may well have precipitated the Soviet decision to move against Berlin. The Russian scholar Sergei Goncharov, reviewing Soviet archives, reports that “during the prolonged Berlin crisis… Stalin was riveted by the possible inclusion of West Germany in the developing American alliance structure. That move would greatly enhance the West's potential for encirclement, and he sought to block it at all costs.” Cecil notes that “at that date negotiations with the USSR for a peace treaty with Austria were well advanced; for reasons that have never become clear the Russians went into reverse; seven years elapsed before they were finally convinced that we envisaged a neutral, independent Austria on the model already under discussion in 1948.”

Berlin had been unstable even before the secret Pentagon meetings; Marshal Vassily Sokolovsky, the Soviet military governor, Clay's counterpart, had walked out of the Allied Control Council in Berlin on March 20, whereupon the Soviets began to manipulate Allied rail access. Even this first Soviet sally raised the question of atomic war in the minds of US military leaders. Major General Kenneth Nichols, an Army engineer who had been Groves's deputy during the war, had succeeded Groves as commander of the Armed Forces Special Weapons Project (AFSWP) on January 1 (Groves retired from the Army on February 29). On March 31, over lunch, Nichols briefed Forrestal, the Joint Chiefs (which then included Dwight Eisenhower) and the armed-service secretaries:

Clay had reported further restrictions on our land transportation, and he threatened to confront the Russians if they stopped and boarded any train, to shoot if necessary. I was at the meeting to supply information about whether, if the crisis grew worse, we were in a position to deliver any atomic weapons. We were not. I told them that the only assembly teams, military and civilian, were at Eniwetok for the Sandstone test and that the military teams were not yet qualified to assemble atomic weapons. I was told in very definite terms by Eisenhower to accelerate training and improve the situation at once… Action was initiated to perfect plans for transfer of atomic weapons to the military in case of emergency and to expedite training and equipping the military assembly teams.

Sandstone was the designation of the first test series of new atomic weapons that Los Alamos was then preparing at Eniwetok atoll in the Marshall Islands. Sandstone X- Ray, a composite-core, levitated implosion device, would be exploded on April 15, 1948, with a yield of thirty-seven kilotons. Two other tests would follow: Yoke, on May 1, another composite, levitated core that yielded 49 KT, the largest yield yet coaxed from any atomic weapon, almost four times that of the Hiroshima bomb; and Zebra, on May 15, a levitated all-U235 core that yielded 18 KT. An uninvited Soviet warship would be on hand to watch the proceedings from twenty miles off, as well as at least one submarine. The Sandstone tests demonstrated that small amounts of fissionable material could develop large yields. A levitated composite core typically used less than half as much plutonium as a solid Christy core and ten times less U235 than a Little Boy gun. “The most immediate military effect of Sandstone,” the independent scholar Chuck Hansen notes in his authoritative history of US nuclear weapons development, “was to make possible within the near future a 63 percent increase in the total number of bombs in the stockpile and a 75 percent increase in the total yield of these bombs… Sandstone also proved conclusively that implosion of U235 was far more efficient than assembling it in a gun-type weapon and demonstrated that current implosion theory was sound… The results of Sandstone were characterized [in contemporary reports] as ‘radical’ and representing ‘substantial’ improvement in the military position of the US.” Carson Mark would note that the tests “marked the end of the day of the atomic device as a piece of complicated laboratory apparatus rather than a weapon… The number of units which could be made from the existing stock of plutonium and uranium could [now] be increased appreciably merely by refabricating the fissile parts of the weapons by hand.” While the Soviet Union challenged the United States over access to Berlin, however, the crews Los Alamos had trained to assemble atomic weapons were off in the Pacific six thousand miles from Albuquerque, where the 509th would pick up the US's meager store of bombs were there someone on hand to assemble them.

Without atomic backup, the Joint Chiefs reined Clay in; his modest forces in Germany avoided confrontation by taking to the air. “During one period of eleven days in early April,” LeMay recalls, “when the Soviets demanded the right to search and investigate all military shipments by rail, we flew small quantities of food and other critical supplies into Berlin; something like three hundred tons.” Clay discontinued the little airlift in mid-April when the Soviets eased back. The Marshall Plan had become US law on April 3.

From February to May 1948, the Joint Chiefs had been charting and revising a series of emergency war plans. They approved BROILER in March, modified it to FROLIC and finally approved HALFMOON in early May. HALF-MOON included an Air Force atomic annex, HARROW, which envisioned dropping fifty atomic bombs (the entire stockpile that spring) on twenty Soviet cities, causing “immediate paralysis of at least 50 percent of Soviet industry.” Such paralysis would not be sufficient to stop the Red Army, HALFMOON foresaw; the plan expected that Soviet forces would overrun Western Europe at the outset of any conflict. Truman's chief of staff, Admiral William D. Leahy, briefed the President on HALFMOON on May 5. Truman was not happy to be saddled with a war plan that counted on atomic weapons. He told Leahy that such weapons might be outlawed before war came and that the American people in any case would not tolerate using atomic bombs for “aggressive purposes” and he ordered an alternative plan developed that depended on conventional forces alone.

Any immediate possibility of outlawing atomic weapons was foreclosed on May 17 when the United Nations Atomic Energy Commission, still carrying on the negotiations that Bernard Baruch had begun for the US the previous summer, announced that it had reached an impasse and recommended suspending its work. By then the US and the Soviet Union had danced one more diplomatic dance. On May 4, Bedell Smith in Moscow delivered a note to Molotov intended to reassure the Soviet leadership after the March war scare. The note protested that “the United States has no hostile or aggressive designs whatever with respect to the Soviet Union” and declared in a key sentence that “as far as the United States is concerned, the door is always wide open for full discussion and the composing of our