Nuclear Threats - Korea / Truman - 1951

It is commonly believed that it was the threat of atomic warfare that forced an armistice in Korea in 1956. John Foster Dulles, who conveyed that threat, believed it to have been effective. This belief became a cornerstone of US foreign policy for the remainder of the decade, in which China was several times threatened with the bomb. Whether this ruse was truly effective is now the object of debate.

US strategists believed that they enjoyed a clear, if limited, nuclear superiority over the Soviet Union. In view of Soviet ascendancy in conventional warfare, particularly the Soviet numerical advantage in Europe, they felt nuclear superiority ought somehow to be used (having first presumed it usable.) They thought that the combination of restraint and resolve employed in the Berlin Crisis had worked and would work again.

In June 1950, America had a stockpile of nearly three hundred bombs, with over two hundred and sixty aircraft capable of dropping them on Soviet targets. The USSR, which had exploded its first bomb only ten months earlier, could strike America only with one-way bombing flights or by smuggling weapons into American ports aboard merchant vessels. While both sides dramatically increased their stockpiles during the first years of the Korean War, the overall balance remained similarly skewed until 1953.

In 1953, no nuclear bombers were deployed outside the American mainland. While war plans called for the atomic strikes against Soviet cities, Strategic Air Command estimated it would take three months to bomb Moscow into submission, during which during which time there would be a strong possibility of a counter-strike on American soil. By 1953 jet bombers, aircraft carriers and overseas bases had made swift atomic warfare possible; yet the Pentagon still did not have custody of any complete nuclear devices and the State Department had not yet begun negotiations for the foreign deployment of nuclear weapons. This meant that Washington had no immediately usable nuclear forces near Korea.

Nevertheless, use of the bomb was contemplated by Truman and Eisenhower from the outset. Eisenhower’s ‘New Look’ strategy would champion reliance on nuclear weapons and strong alliances as deterrents to Communist aggression.

The possibility of nuclear warfare emerged in Truman’s first wartime meeting with his advisers, when he asked his Air Force Chief of Staff if it were possible to destroy Soviet bases near Korea. The answer was that this was achievable; but would require the use of atomic bombs. Truman ordered the preparation of plans for launching an atomic attack, should the Soviet Union join the fighting. Yet while the US administration sought to “let the world know we mean business,” the overall response remained cautious. Rejecting CIA director Roscoe Hillenkoetter’s proposal to seek UN sanction for use of the bomb, Truman limited himself to authorizing the Pentagon to exceed its budget and use the draft.

Two days later, the Joint Chiefs of Staff (JCS) postponed a decision on a request from General MacArthur for more troops and set aside the Chairman’s proposal that atomic weapons be put at the General’s disposal. These decisions reflected doubts about MacArthur’s judgement, foreshadowing his clash with the President and eventual dismissal. Strategically, they showed a reluctance to disrupt European alliances and hesitance to deploy atomic weapons where they might not prove decisive. In the interim, a decision was made to repeat the B-29 feint of 1948 (See Berlin.)

The B-29s deployed during the Berlin crisis had had no atomic bombs on board. This time, despite British reluctance, the B-29s were armed with all components of their atomic weapons save the fissionable cores. In this respect, America was concerned as much with signalling resolve to the wavering British as deterrence of Soviet aggression.

By the last week of July, MacArthur’s forces had been squeezed inside a ninety-nine mile perimeter in a continuing retreat. At the same time, the commander of the seventh fleet reported that his position in the Taiwan Strait was becoming untenable. MacArthur told Vandenberg, the Air Force Chief of Staff that he saw “a unique use for the atomic bomb” in isolating the Chinese communist force in North Korea. If Vandenberg could “sweeten up” the B-29 force at his disposal, the job could be done. When Vandenberg returned to Washington, the scheme was altered to meet the demands of the increasingly desperate military situation, with emphasis on atomic strikes against North Korean cities. Truman, who had refused pleas for a pre-emptive strike against the Chinese amphibious force amassing across the water, was persuaded to authorize the dispatch of ten nuclear-configured B-29s to Guam. To make Moscow and Beijing, details of the deployment were deliberately leaked to the New York Times.

It is impossible to tell if this signal of resolve was picked up in China or the USSR. It is likely that at least part of the reasoning behind it was to counter internal criticism of Truman’s handling of the war. What is certain is that China did not back down as a result: The Chinese did not invade Taiwan, instead moving crack military units to the northeast where they began preparation for action in Korea in August. The B-29s took no part in the bombing of North Korea and returned to the US before the Chinese offensive.

When in November 1950 Chinese troops poured across the Yalu, halting the UN forces’ conquest of the Korean peninsula, there was renewed talk of atomic retaliation. Truman told the press he would take “whatever steps necessary” and indicated that the use of nuclear weapons had always been “under active consideration.” When he added that the commander in the field would be “in charge of their use,” a crisis erupted. British Prime Minister Clement Attlee flew immediately to Washington and with Strategic Air Command (SAC) awaiting orders for nuclear deployment, the crisis reached its peak.

The orders never came. There were several reasons for this: The months since the first crisis of the summer had seen a change in attitude among strategic planners. They felt that once Chinese forces were in North Korea, the bomb would be better used for defence than deterrence. This coincided with a feeling in the State Department that atomic strikes would scare allies more than enemies. On the ground in Korea, the situation was stabilizing and commanders expressed cautious optimism. The JCS recommended Attlee be told America had “no intention” of using nuclear weapons unless they were needed to protect an evacuation of UN forces or to prevent a “major military disaster.”

Although the use of the bomb was never seriously considered, the November crisis had several important consequences: One was to limit the potential use of nuclear weapons to covering the retreat of US forces—in January 1951, MacArthur refused even to consider forward deployment of nuclear weapons for that purpose. Another was the beginning of reform of the ad hoc decision-making process for nuclear deployment, which had proved itself inadequate. Responsibility was transferred in large part to a new National Security Council (NSC) committee.

By April 1951, the United States had returned to the offensive and UN troops were poised to cross the 38th parallel in force. The Chinese, however, appeared to massing for an offensive of their own. Washington also had indications that Moscow had moved three divisions into Manchuria and had positioned other forces to attack Japan.

At home, divisions among strategists were widening. MacArthur’s statement that the UN might abandon its “tolerant effort” to limit the fighting to Korea infuriated the President’s civilian advisers and provoked protest from Britain. Truman’s relationship with congress deteriorated and his popularity fell to an all-time low. It was widely suggested that the people lacked confidence in their leaders’ ability to end the war.

When on April 4th UN troops crossed the parallel, discord in Washington intensified. MacArthur’s headquarters in Tokyo denied the existence of a Soviet build-up, at the same time claiming that the general was authorised to retaliate against a Soviet attack. In Washington, Senate minority leader Joseph Martin read publicly a letter from MacArthur which implied the administration misunderstood the global strategic significance of the Korean conflict. An unmistakable challenge to Truman’s leadership, the letter set in motion the train of events that would remove the general from command.

On 6th April 1951 Truman took the decision to return B-29s across the Pacific, this time with complete atomic weapons. This followed the Chief of Staff’s recommendation that MacArthur be authorised to retaliate against air bases and aircraft in Manchuria and Shantung in event of an attack originating outside the Korean peninsula. Summoning the Chairman of the Atomic Energy Commission, Truman told him that with aircraft accumulating in Manchuria and Soviet submarines in Vladivostok, he feared the Soviet Union was preparing a knockout blow. Arrangements were begun for the transfer of nine complete atomic bombs to Air Force custody.

But the military situation was not as desperate as Truman claimed. Once again, domestic considerations were important: The nuclear deployment was essential in securing the support of the Chiefs of Staff for the dismissal of MacArthur. On 8th April, they agreed to support Truman’s decision to remove the general.

The next evening, Truman publicly defended his action against MacArthur. Without making reference to the B-29s deployment, he warned Beijing and Moscow against escalating the conflict, with the aim was of showing both determination and restraint. Restraint was not the strategy advocated by MacArthur, who in an impassioned speech to congress claimed the Joint Chiefs shared his view that escalation could bring victory in Korea. MacArthur was certainly right in respect: Truman’s veiled warnings had left the Chinese undeterred. Soon after MacArthur’s speech, they launched their biggest ground offensive yet.

The administration realized more must be done and the Pentagon began to hint that the B-29 deployment more than a routine mission or a feint. Truman approved a second bomber deployment and SAC sent a team to Tokyo, where its commander began planning for possible atomic strikes. Ridgway, MacArthur’s successor, received qualified authority to launch atomic strikes in retaliation to an attack originating outside the peninsula. Reconnaissance aircraft flew over Manchuria and Shantung and messages were conveyed to Beijing, to show that MacArthur’s removal did not signify a softening in nuclear policy.

The Chinese would eventually back down. Yet it is unclear that Chinese leaders were aware of the nuclear deployment in the Pacific. It is as likely Beijing’s eventual shift to a defensive policy was prompted more by the failure of two offensives than by the nuclear threat. Rather than setting a precedent for nuclear deployment, the events of 1950-51 reinforced the reluctance of the Truman administration to use atomic weapons and were seen as one-off responses to particular circumstances. There did emerge, however, a strength of belief in the persuasive power of nuclear diplomacy.