| Beginning in the late 19th century, Japan fought a series of wars that expanded its control over the Asian mainland. By the beginning of World War II in 1939, Japan had a sizeable empire in East Asia. On December 7, 1941 Japan made a major military push into Southeast Asia and the Pacific, simultaneously launching an attack against the United States. The Japanese empire reached its height shortly thereafter, in 1942. After that, Allied military forces began to push the Japanese back toward their home islands. Japan lost all of its colonial territories after its defeat in World War II. |