Richard Rhodes writes in his 1995 book, Dark Sun: The Making of the Hydrogen Bomb:
IN THE MONTHS immediately postwar, United States military and intelligence organizations wheeled their attention like heavy artillery around from Germany and Japan to the Soviet Union. Not only did real Soviet forces on the ground in Europe challenge, by their continued presence, the demobilizing Western defense; the Soviet Union was also the only theoretical enemy visible, as far ahead as it was sensible to look. In a first working estimate of the number of atomic bombs the US should stockpile, for example, confined to the years 1945 – 1955 when conventional bombers would still be the only available means of delivery, US Army Air Forces Major General Lauris Norstad pointed out that “during this period Russia and the United States will be the outstanding military powers,” and for that reason the estimate used “the destruction of the Russian capability to wage war . . . as a basis upon which to predicate the United States atomic bomb requirements.” 973 To General Groves, who continued by default to direct the atomic weapons program, the Soviet Union had always been the ultimate adversary; from the beginning, Groves had guided the Manhattan Project in the direction not of making a few bombs to end a war but of developing a broad industrial capability to turn out atomic weapons in quantity after the war was won. Regardless of political views, responsible contingency planning required military leaders to consider from which direction war might come and what forces and strategy they would need to forestall it or to claim victory. This planning proceeded even as the United States government attempted to negotiate through the United Nations a program of international control of atomic energy. Such cross – wired confusion about the application of nuclear energy to war and international relations would trouble American atomic policy for years to come.
On August 8, 1945, between the Hiroshima and Nagasaki bombings, USAAF General Carl Spaatz, anticipating “plans for [a] post – war atomic – bomb program,” stressed in a memorandum that “the atomic bomb is essentially an air weapon” and “there must be a plan for orderly transition from the present to a post – war basis which envisions our ability on short notice to deliver atomic bombs. . . . ” 974 Spaatz proposed that the 509th Composite Group, which had been organized under Colonel Paul Tibbets to drop the first atomic bombs, “should remain intact as a nucleus for an expanded program.” 975 Spaatz was commander of the Pacific Air Force at the time; in 1946 he became commanding general of the air forces. The 509th, renamed the 509th Bomb Group, which operated the only aircraft equipped to carry atomic bombs, moved to Roswell Army Air Base in Roswell, New Mexico, soon after the war.
The US Joint Chiefs of Staff met secretly before the atomic bombings of Japan and approved a new policy of “striking the first blow” — surprise attack — in the event of an atomic war. 976 The first – strike policy found embodiment subsequently in a planning document issued on September 20, 1945, which stressed that during a crisis, while diplomacy proceeded, the military should be “making all preparations to strike a first blow if necessary.” 977 Surprise attack went against previous US military policy, which had been formally defensive, as well as national tradition, but the change was not gratuitous. To the Joint Chiefs it seemed to follow logically from a realistic assessment of the destructiveness of nuclear weapons: whoever struck first with such powerful weapons was likely to carry the day. “Offense,” the Joint Chiefs would assert two years later, “recognized in the past as the best means of defense, in atomic warfare will be the only general means of defense.” 978 In that spirit, by October 1945, the JCS Joint Intelligence Committee began drafting a plan for a first strike on the Soviet Union of twenty to thirty atomic bombs, a number based on a realistic assessment of currently available resources of ore and manufacture. 979 The plan foresaw two scenarios that might require such a strike: in retaliation for Soviet aggression or, when the Soviet Union became capable of attacking the United States or of repelling a US attack, as preventive war.
Groves also mulled preventive war in those first heady months of nuclear monopoly. “If we were truly realistic instead of idealistic, as we appear to be,” he wrote in a secret report, “Our Army of the Future,” “we would not permit any foreign power with which we are not firmly allied, and in which we do not have absolute confidence, to make or possess atomic weapons. If such a country started to make atomic weapons we would destroy its capacity to make them before it has progressed far enough to threaten us.” 980 The Joint Intelligence Committee plan explored doing just that.
What the US military planned contingently and some military leaders vigorously advocated was not official policy. The US government never endorsed or authorized preventive war. Harry Truman evidently found the idea morally repugnant as well as politically suicidal. “Such a war is the weapon of dictators,” the President said publicly in 1950, “not of free democratic countries like the United States.” 981 But the extreme conviction that the only sure way to protect America from what one Air Force general, Nathan Twining, would call “the whims of a small group of proven barbarians” was to destroy the industrial capacity of the USSR preemptively — to strike Soviet cities by surprise with atomic bombs, that is, with the potential loss in a few apocalyptic days of tens of millions of human lives — persisted within the military, the USAAF in particular. 982
Norstad’s more ambitious study of September 1945, which incorporated the strategic chart of Russian and Manchurian urban areas that Groves had seen in late August, found that the Soviet Union could be defeated at the outset of a war if the United States destroyed sixty – six Soviet “cities of strategic importance,” neutralized a few air bases the Soviets might use outside the USSR and isolated “the battlefield” by atomic – bombing such tactical targets as the Dardanelles and the Kiel and Suez Canals. 983 For these purposes, and estimating that only 48 percent of the bombs would get through and find their targets, Norstad concluded that the United States would need to stockpile 466 atomic bombs of Nagasaki scale. The USAAF general sent his study to Groves for comment. Groves dismissed this first air effort impatiently. It underestimated the destructiveness of atomic bombs, he told Norstad, and overestimated how destructive they would need to be to disable a city. “My general conclusion would be that the number of bombs indicated as required, is excessive.” 984
The day before Norstad sent his study to Groves for review, September 14, he and USAAF Lieutenant General Hoyt Vandenberg had been appointed to a board headed by Carl Spaatz charged to report on “the effect of the atomic bomb on the size, organization, composition, and employment of post – war Air Forces.” 985 A few of Norstad’s findings made their way into the report the Spaatz Board issued in October, but overall its conclusions were cautious. It noted that the USAAF knew very little about atomic bombs because of Manhattan Project secrecy, which the President had recently extended postwar. The weapon was large, heavy, “enormously expensive and definitely limited in availability.” For these and other reasons, the Spaatz Board recommended that the USAAF wait and see, concluding that “the atomic bomb does not at this time warrant a material change in our present conception of the . . . Air Force.” 986 The board proposed assigning a bloodhound to follow the trail — a new Deputy Chief of Air Staff for Research and Development — and recommended appointing Curtis LeMay, just back from Hokkaido in his long – range B – 29.
Production that autumn from Oak Ridge and Hanford confirmed the limits the Spaatz Board had assessed. 987 Oak Ridge separated 1.063 kilograms of U235 per day at a daily cost of $158,300. The Little Boy uranium gun used sixty – four kilograms, which was two months’ production (six Little Boys per year), and with composite cores in the offing for the implosion bomb, Groves decided to stockpile the U235 rather than make it up into wasteful and obsolete guns. Hanford produced about four to six kilograms of plutonium per month, enough for about ten to twelve Fat Man bombs per year (with just over 6 kg of plutonium per core), but composite cores would need only 3.2 kg of plutonium each (plus 6.5 kg of U235). So the only bomb assemblies Los Alamos produced for the rest of the year and during 1946 were Fat Man designs, now called Mark IIIs, which could accommodate a solid Christy core or a new composite. The composite, however, could not be certified for military use until the design had been tested at full scale, and no such test was in the offing. Effectively, then, the US production of U235 — by far the larger quantity of fissionable material — was long – term reserve with no short – term military application.
