On September 24, 1949, almost four weeks after the Soviet nuclear test, the Soviet Politburo instructed the North Korean leader, Kim Il Sung, not to attack the South. North Korea, it said, was not prepared in military or political terms for such an attack. Four months later, on January 30,1950, Stalin let Kim know that he was now willing to help him in this matter.585 Why did Stalin change his mind? When Kim visited Moscow in March and April, Stalin explained to him that the Chinese communists could now devote more attention to Korea. The Chinese Revolution was evidently more important than the Soviet bomb in Stalin’s decision to support Kim. Stalin cannot have thought that the nuclear balance of forces had changed very much, because the Soviet arsenal grew very slowly; it was not until November i and December 28, 1949, that the Soviet Union had enough plutonium for its second and third bombs. 586
The war did not turn out as Moscow and Beijing had hoped. The United States intervened under the auspices of the United Nations and, as UN forces advanced into North Korea, the Chinese, who had supported Kim’s plans, had to decide whether or not to enter the war. Those opposed to entry feared that the United States would use the atomic bomb in order to avoid defeat. Those in favor argued that China’s alliance with the Soviet Union, which now had the bomb, would deter the United States from using nuclear weapons.587 Stalin stiffened Chinese resolve by reassuring Mao Zedong that the United States
Was not ready for a "big war” and that, in any event, China and the Soviet Union together were stronger than the United States and Britain.588
China’s entry into the war caused alarm in Washington. On November 30, 1950, Truman created the impression, in answer to a reporter’s question, that the atomic bomb might be used in Korea at General Douglas MacArthur’s discretion. This caused an outcry. Clement Attlee flew to Washington on December 4 for reassurance that Truman was not actively considering the use of the bomb and that the decision to use it would remain in the president’s hands.589 Truman did not seriously consider using the bomb during the Korean War. He deployed nuclear-capable B-29s to Britain and to Guam in July 1950 but without nuclear weapons. The purpose was partly, as in the Berlin crisis, to signal American resolve and partly to enhance strategic readiness for a possible war. The bombers in Guam were soon withdrawn. In April 1951, Truman authorized the deployment of B-29 bombers and nuclear weapons to Guam. This was the first time since 1945 that the United States had sent nuclear weapons abroad. The purpose of the deployment was to be ready to respond in case the Soviet Union should enter the war. The bombers and the weapons were withdrawn in July, once the armistice talks began.
The Pentagon and the State Department studied at various times the possible use of the atomic bomb in Korea, but the studies only pointed up the difficulties. There were few good targets in Korea itself: using the bomb on the battlefield would produce little effect if Chinese and North Korean forces were dispersed, and it might harm UN forces if the two sides were engaged in close battle. Using the bomb against Chinese or Soviet bases in Manchuria, or against Chinese cities, would lead to an expansion of the war, which Washington wanted to avoid. Besides, United States allies in NATO were strongly opposed to the use ofthe bomb, and to use it once more against Asians might undermine the American position in Asia.
Truman was forthright in defending his decision to bomb Hiroshima and Nagasaki but he did not want to use this terrible weapon again. President Eisenhower was more willing to contemplate its use. He told the NSC on February 11, 1953, that the United States should consider employing tactical atomic weapons in Korea. At the same meeting, Secretary ofState John Foster Dulles spoke of inhibitions on the use of the bomb, and of "Soviet success to date in setting atomic weapons apart from all other weapons as being in a
Special category.”590 At an NSC meeting on March 31, Eisenhower commented that he and Dulles "were in complete agreement that somehow or other the tabu which surrounds the use of atomic weapons would have to be destroyed.”591 The Eisenhower administration dropped hints that it would resort to nuclear weapons to bring the Korean War to an end, and it deployed nuclear weapons to Guam. Eisenhower later claimed that it was the threat to use the bomb that made possible the armistice signed on July 27,1953. Recent evidence from the Russian archives suggests that, whatever role indirect nuclear threats may have played, it was Stalin’s death on March 5 that was the key event in bringing the war to an end.592
Military planners thought of the bomb as another weapon to be used in war, but policymakers, influenced perhaps by the peace movement and public opinion, saw it as being in a class of its own. Eisenhower and Dulles regarded this as a constraint and complained about it. Putting the bomb in a special category made it more difficult to use, because its use would have to be justified by special factors. The distinction between "conventional” and "nuclear” weapons began to emerge at the end of the 1940s, reinforcing the idea that the bomb belonged in a special category. Each side was willing to put intense pressure on the other, but - as Soviet and US policy in the Korean War made clear - neither wanted what Stalin called the "big war.” Viacheslav Molotov said many years later that the Cold War involved pressure by each side on the other, but "of course you have to know the limits.”593 The bomb, because it was so dearly in a category ofits own, marked one important limit: to use it would mean crossing a significant threshold on the path to general war.
World History
