The Korean War began in June of 1950 when the army of North Korean dictator Kim Il-Sung crossed the 38th parallel into South Korea, capturing Seoul and driving the unprepared American and Republic of Korea (ROK) forces in pell-mell retreat down the peninsula. The American government saw this invasion as a confrontation with the Soviet Union that posed the question: should the United States employ atomic bombs as tactical weapons?

Imminent Chinese Threat

On September 15th, General Douglas MacArthur, the Supreme Commander of United Nations forces in the Far East, invaded Inchon, a western port city not far from Seoul, and dramatically turned the tide of the war. North Korean forces that had besieged the Americans and ROK forces in Pusan now retreated hastily northward. Instead of stopping at the 38th parallel, however, MacArthur ordered his forces to pursue the North Koreans all the way to the Yalu River, which marked the border of North Korea and China. Threatened, the Chinese attacked American and UN forces in strength in late November.

Refusing to Rule Out Atomic Weapons

In August of 1950, President Harry S. Truman had decided to send the U.S. Air Force’s 9th Bomb Wing to Guam, carrying atomic bombs. At a press conference on November 30th, Truman -- who had made the decision to drop two atomic bombs on Japan -- refused to rule out the use of nuclear weapons against the Chinese. While the Soviet Union had just tested their first atomic bomb, the United States still had overwhelming nuclear superiority and could essentially have bombed Russia and China unchallenged. However, American military and strategic planners had serious reservations about using nuclear weapons in the way that they might convention bombing.

Would The Bomb Work?

The American government was concerned about what the public would think of the United States using the atomic bomb in Korea, given the massive loss of life at Hiroshima and Nagasaki, and given the fact that 49 percent of Americans, by January of 1951, disapproved of U.S. involvement in the war. There was also the question how world opinion would take another mass slaughter of Asians. But there were tactical consideration, as well. American planners did not have a real strategy thought out for using nuclear weapons in a limited war. The Chinese did not have the kind of targets American military planners sought -- industrial centers and huge transportation hubs. The bomb would be used on the Chinese regiments infiltrating through mountain passes into the south. But because the bomb was designed for use against concentrated targets, the United States was uncertain if it would actually work to stop the Chinese.

Losing Credibility

The specter of nuclear weapons not stopping the Chinese was the chief fear that haunted the Americans at the time. For if atomic weapons were not seen as an effective deterrent, then they would lose their credibility as the threat that was supposed to stop the spread of Communism. Americans realized that for the atomic bomb to work, it was better that it not be used at all, except under the most dire circumstances. So they resigned themselves not only to the grinding stalemate that became the Korean War, but also to the larger Cold War.