Japan, U.S. Military Involvement in. Initial U.S. military involvement with Japan occurred in 1853, when Comm. Matthew C. Perry led a naval expedition there. Perry sought to compel the ruling Tokugawa Shogun to open Japan to foreign commerce on American terms. In the face of superior technology, the Japanese acceded to Perry's demand in 1854. In the early twentieth century, despite disputes over immigration restriction and mistreatment of Japanese residents in the United States, the two Pacific nations became major trading partners and cooperated in creating a balance of power in the Asia‐Pacific region. The collapse of world trade after 1929, however, prompted Japanese militarists and nationalist politicians to abandon the framework of cooperation established with the West under the League of Nations (1919) and Washington Naval Arms Limitation Treaty (1922) and to seek creation of a self‐supporting Japanese empire. In 1931, the Japanese Army seized Manchuria, and in 1937 it invaded China proper.

Japan's cooperation with Nazi Germany from 1936 on, as well as its threat to the American and European colonies in Asia, prompted the Roosevelt administration to begin aiding China in 1938. By July 1941, Japan's occupation of French Indochina prompted PresidentFranklin D. Roosevelt to embargo all sales to Japan and boost military aid to China. Months of fruitless negotiations culminated in the attack on Pearl Harbor, 7 December 1941.

In the three months following the outbreak of war, Japanese air, sea, and land forces swept over colonial Southeast Asia and the western Pacific, including the Philippines. Although Roosevelt and his military advisers adopted a “Europe‐first” strategy, they were able to send sizable military and naval resources to the Pacific before Germany's defeat. U.S. intelligence also broke important Japanese naval codes. By the end of 1942, the Japanese lost the initiative in the Pacific. American forces then embarked on the long push to Tokyo.

In the spring of 1945, the Army Air Force began massive raids on Japanese cities. At about the same time, after incredibly bloody fighting, U.S. forces seized two strategic islands, part of Japan's inner defense ring, in the battles of Iwo Jima and Okinawa. In June, President Harry S. Truman authorized plans for the invasion of Japan, tentatively scheduled for November. The successful testing of the atomic bomb that July provided the United States an alternative to invading the home islands. The shock of the new weapon, U.S. strategists hoped, would convince deadlocked Japanese decision makers to surrender quickly. Besides saving lives on all sides, an early surrender might keep Soviet troops from occupying China and gaining a foothold in Japan.

The air force dropped the first atomic bomb on Hiroshima on 6 August 1945, the second against Nagasaki 9 August. The combined shock of the atomic bombs and the Soviet entry into the war prompted Japanese emperor Hirohito to break the deadlock among his advisers in favor of agreeing to U.S. surrender terms. President Truman accepted the surrender 15 August 1945, and the Japanese signed surrender documents at a ceremony aboard the battleship Missouri in Tokyo Bay 2 September. Over 2 million Japanese (including some 400,000 civilians) and 100,000 Americans died in the Pacific War.

The American military occupation of Japan lasted from August 1945 through April 1952. Gen. Douglas MacArthur served as Supreme Commander of the Allied Powers until his removal in April 1951. Gen. Matthew B. Ridgway succeeded him. Among the many liberal reforms instituted by the Americans was Article 9 of the new Japanese Constitution barring the establishment of armed forces or the right to conduct war, a clause regretted by U.S. policymakers in the Cold War. When the Korean War broke out in June 1950, the United States ordered Japan to create a small “national police reserve” that assumed the defense duties of American forces shifted to Korea. Gradually, this evolved into Japan's Self‐Defense Forces.

In September 1951, when the United States and its allies signed a peace treaty with Japan, it compelled Tokyo to sign a bilateral security treaty with Washington that permitted sizable American forces to use military bases in Japan indefinitely. The arrangement, which many Japanese saw as a demeaning continuation of the occupation, was extremely unpopular. However, it was understood as the price that must be paid to regain sovereignty. The treaty was revised in 1960 to make it more equitable.

During the Korean and War the Vietnam War and in Cold War strategy, military base and logistic facilities in Japan were vital for U.S. military operations. In the late 1990s, sizable American military units remained stationed on Okinawa and Japan proper. Since the early 1950s, the United States has encouraged Japanese rearmament and urged Tokyo to take a more active role in Asian security matters. Public opinion in Japan has resisted expanding the limited role of the Self‐Defense Forces, but the Japanese government appeared ready by the late 1990s to play a more active role both in regional military defense and in international peacekeeping operations.
[See also Hiroshima and Nagasaki, Bombings of; Japan, Peace Treaty with; MAGIC; World War II: Military and Diplomatic Course; World War II, U.S. Air Operations in: The Air War Against Japan; World War II, U.S. Naval Operations in: The Pacific.]

Bibliography

Michael Schaller , The American Occupation of Japan: The Origins of the Cold War in Asia, 1985.
Ronald H. Spector , Eagle Against the Sun: The American War with Japan, 1985.
John Dower , War Without Mercy: Race and Power in the Pacific War, 1986.
Michael Barnhart , Japan and the World since 1868, 1995.
Walter La Feber , The Clash: U.S.‐Japanese Relations Throughout History, 1997.
Michael Schaller , Altered States: The U.S. and Japan Since the Occupation, 1997.

Michael Schaller