William Borden expressed similar reservations in late November, when MacArthur was agitating for attacks on North Korean supply lines and bases in Manchuria; Borden told Brien McMahon he opposed atomic bombing in Korea “for three reasons: (1) propaganda capital could be made of their use in the Far East; (2) the fact that each weapon used in Korea would leave one less to be used if necessary against Russia; and, (3), most important of all, I fear that use of these weapons in Korea would not be effective in quickly ending the Korean war and would, therefore, result in an enormous psychological down-grading of the value now attached to atoms.”
In August, when LeMay's atomic-capable aircraft were ferrying unarmed atomic bombs to the Far East, the Chinese were already preparing to enter the war. North Korean forces were then pushing the beleaguered United Nations defenders nearly to the end of the Korean peninsula, where they would make a last stand at Pusan. The Chinese had war-gamed MacArthur's options and foreseen that he would launch a counteroffensive by sea on the west coast just below Seoul at Inchon, cutting the overextended North Korean supply lines and trapping Kim II Sung's armies. (The Chinese warned Kim of the danger, but he chose not to believe them.) “If we do not intervene in the Korean War,” Mao told his advisers, “the Soviet Union will not intervene either… once China faces a disaster.” The Chinese Politburo had concluded that the US would not use atomic bombs if China intervened in Korea because doing so would risk possible Soviet retaliation and because bombing into what the Chinese called “jigsaw pattern warfare” in the Korean mountains would put UN forces at risk. The Chinese also believed that the US was so heavily committed in Europe that it had only limited resources to devote to Korea. (What resources the United States had to spare was indicated at the beginning of October, when Truman approved a joint recommendation of the Atomic Energy Commission and the Department of Defense to spend $1.4 billion — at a time when the entire Defense budget was under $15 billion — to expand uranium and plutonium production facilities, doubling the US capital investment in military atomic energy. In June, Truman had approved construction of two heavy-water reactors at a site on the Savannah River near Aiken, South Carolina, for tritium production at an estimated cost of $250 million. In October, he approved plans for three more.)
US intelligence found some indication of Chinese movement as early as August 30, when LeMay's diary reports news from the Pentagon “that the Chinese have decided to aid the North Koreans, and that four Chinese armies have crossed the border into NK. Many airfields in North Korea are being readied for aircraft which could only be coming from either the Chinese or Russians.” The information on army movement at least was garbled and inaccurate (the Chinese New 4th Army was drilling and maneuvering at the time along the Korean border), and no further information came to SAC about it. MacArthur landed his forces at Inchon on September 15. After fighting their way inland, they crossed into North Korea on October 1 and began pushing north toward the Yalu River, which divided Korea from China. The Inchon counteroffensive had shocked Stalin; Chinese sources claim he promised them air cover in response if they intervened on North Korea's behalf.
Mao's armies — twelve, not four — were supposed to begin moving across the Yalu into North Korea in mid-October. “We have decided to send part of the armed forces into Korea,” Mao telegraphed Stalin on October 2, “to do combat with the forces of America and its running dog Syngman Rhee and to assist our Korean comrades.” Mao's order officially entering the war was issued on October 8. That night, when Kim II Sung heard the news, he clapped his hands and shouted, “Well done! Excellent!”
But Stalin immediately reneged on his promise of air cover and stalled the Chinese assault. “When the threat emerged [after Inchon],” Nikita Khrushchev recalled, “Stalin became resigned to the idea that North Korea would be annihilated, and that the Americans would reach our border. I remember quite well that in connection with the exchange of opinions on the Korean question, Stalin said, ‘So what? Let the United States of America be our neighbors in the Far East. They will come there, but we shall not fight them now. We are not ready to fight.’” Mao and his advisers agonized for most of a week before deciding to go ahead with or without Soviet support, but when that decision reached Moscow, Stalin changed his mind once more and again offered support. The Chinese began crossing the Yalu on October 19 without Soviet air cover, but between October and December, Stalin sent thirteen air divisions to the Korean area. Ten Soviet tank regiments moved into Chinese cities for rear-area defense.
LeMay's diary records a briefing on November 2 confirming “increasing reports of Chinese intervention,” including “attacks by Red jet fighters… against our troops and fighter [aircraft].” By November 28 “the Korean battle” was “going badly” and “the Chinese” had “made mincemeat out of our latest attack. Gen. MacArthur stated that conditions were out of control.” A call to SAC from Vandenberg's office “indicates a feeling of pessimism there on our progress… and a growing feeling that we may have to send more [bomber] units to the Far East to bolster the AF there.”
Truman confirmed at a press conference on November 30 what he had denied the previous summer: that he had been actively considering using atomic bombs in Korea since the beginning of the war. He also said the military commander in the field — meaning Douglas MacArthur — would have charge of the weapons if their use came to be authorized. “Every New York afternoon paper,” writes John Hersey, who reported the story in
On the Saturday after Truman's Thursday morning announcement, LeMay reported to Vandenberg that “our analysis of available targets together with obvious considerations of possible adverse psychological reaction have led us to conclude that the employment of atomic weapons in the Far East would probably not be advisable at this time unless this action is undertaken as part of an overall atomic campaign against Red China.” LeMay proposed to go personally to the Far East to direct any such campaign.
The following week — early December 1950 — the JCS sent word to all military commanders that “the situation in Korea has caused the possibility of a general war to increase greatly.” Truman declared a national emergency on December 16, announcing a decision to enlarge the armed forces by 3.5 million men and install price controls. LeMay wrote the general commanding SAC operations in Korea, Emmett “Rosie” O'Donnell, Jr., at that time about his atomic-bombing preparations. “As you can imagine,” LeMay told O'Donnell, “there is quite a bit of agitation throughout the country to use the A-bomb to support our troops in Korea. In spite of the pressure, I do not feel that the chances of such action materializing are very great. However, until such a time as the Korean campaign has been concluded, there is always the chance that we will be directed to do the job — [So] we are developing a small Shoran bombing capability in SAC, since we are convinced that this is the best method of doing the job [of atomic bombing]… ”
LeMay's US crews had recently tried bombing using Shoran, a short-range radio navigation system, and in 147 bomb releases from 25,000 feet had achieved an average circular error of only 452 feet. The SAC commander asked O'Donnell to set up Shoran units in Korea “in such a way as to cover the most probable areas where critical situations could develop”; he told O'Donnell he was “relying on your good judgment to handle this matter quietly.”
Both the State Department and the Joint Chiefs backed away from atomic bombing in December when MacArthur advised postponing a decision. But the issue reemerged again in early April 1951, a time of great confusion and doubt. MacArthur in particular was increasingly vocal in his opposition to Truman's policy of moving toward a cease-fire, which the Joint Chiefs also resisted. On March 10, MacArthur had asked for a “‘D’ Day atomic capability” to use attacking airfields in Manchuria. Vandenberg discussed the problem with Secretary of Defense Robert Lovett and Air Force Secretary Thomas Finletter on March 14, noting “believe everything is set.” Then MacArthur went too far, writing House minority leader Joseph Martin that there was “no substitute for victory.” Martin read the letter into the
Early in April, some two hundred Soviet bombers moved onto air bases in Manchuria, a move which put them within striking distance of Japan, and the Soviets communicated through the Indian ambassador to China, Sandar Pannikar, that they would initiate such an attack if the US attacked beyond North Korea. There was movement of Soviet submarines as well. The Soviet threat aroused the Joint Chiefs to prepare to escalate to atomic war. On April 5, they ordered atomic retaliation against the air bases in the event of “a major attack” on UN forces. Gordon Dean, the new chairman of the Atomic Energy Commission, had been alerted the night before to the possibility that the JCS might issue such an order. While the Chiefs deliberated on April 5, Dean looked into the procedure for transferring nuclear capsules to the military — the question had never arisen before. Ramey wired LeMay, putting
