The United States led the Allies in the occupation and rehabilitation of Japan following the end of World War II. Between 1945 and 1952, the U.S. occupying forces made widespread military, political, economic, and social reforms.

The leaders of Great Britain, the Soviet Union, the Republic of China, and the United States discussed how to disarm Japan, to deal with its colonies, especially Korea and Taiwan. They also addressed how to stabilize the Japanese economy and to prevent the remilitarization of Japan in the future.

U.S. General Douglas MacArthur led the Supreme Command of Allied Powers (SCAP) for rebuilding Japan. The occupation of Japan was divided into three phases: the initial effort to punish and reform Japan, the work to revive the Japanese economy, and the conclusion of a formal peace treaty and alliance.

The first phase, from 1945 through 1947, involved fundamental changes for the Japanese government and society. The Allies punished Japan for its past militarism by holding war crimes trials. At the same time, SCAP dismantled the Japanese Army and banned former military officers from serving in the new government.

SCAP introduced land reform, designed to benefit the majority tenant farmers and reduce the power of rich landowners, many of whom had supported war and expansionism in the 1930s. MacArthur also tried to transform the economy into a free market capitalist system by breaking up the large Japanese business conglomerates. In 1947, Allied advisors promoted a new constitution that stripped the emperor of political control and placed more power in the parliamentary system. The new constitution also granted greater rights and privileges for women. It renounced the right to wage war and eliminated all non-defensive armed forces.

By late 1947, an economic crisis in Japan led to a new stage of the occupation. Occupation policies were re-focused on economic rehabilitation of Japan by introducing tax reforms and measures aimed at controlling inflation. The most serious problem was the shortage of raw materials required to run Japanese industries and markets for their finished goods. When the Korean War broke out in 1950, Japan became the principal supply depot for UN forces. The U.S. assured Japan that whatever the state of its military, no real threat would be made against Japan.

By 1950, SCAP believed that the political and economic future of Japan was secure. It worked to secure a formal peace treaty to end both the war and the occupation. The U.S. no longer viewed a re-armed and militant Japan as a threat. Instead, the real threat appeared to be the spread of communism, particularly in Asia. The final agreement allowed the United States to keep military bases in Japan.

Source: Occupation and Reconstruction of Japan, 1945–52
Courtesy of U.S. Department of State