The 1930s marked the high point of Japan’s pre-World War II empire, when Imperial Japan’s territory stretched from mainland China to Micronesia. Japan’s empire would grow even larger during World War II, extending almost as far south as Australia, which Japan directly attacked in 1942 and 1943. But after Japan’s defeat in the summer of 1945 the country was occupied and stripped of its imperial possessions.


The 1930s did not mark the beginning of Japan’s imperial ambitions, notes Susan Townsend of the University of Nottingham. Taiwan had been a Japanese possession since 1895, while the brief Russo-Japanese War of 1905 secured Japanese influence in the Manchuria region of mainland China. In 1910 Japan formally annexed Korea. After taking part in World War I on the Allied side, Japan gained the former German territories of Tsingtao and some Micronesian islands in 1919.

Major Events of the 1930s

In September 1931, the Japanese army moved into Manchuria after an explosion damaged a railway line near the city of Mukden. Japanese leaders took the opportunity to set up what they called the autonomous state of Manchukuo, although in reality it was a military state controlled by the army. In the aftermath of the invasion, Japanese delegates walked out of the League of Nations after the League supported China. In 1937 Japanese and Chinese troops clashed at a border crossing near Peking, resulting in a declaration of war. Japanese soldiers moved quickly southward and captured the city of Nanjing along with large swathes of the Chinese coast.

Military Motivation

Japan’s imperial expansion in the 1930s was due to the long-term view taken by the country’s military elite, argues Louise Young, author of “Japan’s Total Empire.” Japanese military leaders believed that seizing control of areas like Korea was vital to securing Japan’s security in the East Asia region. In addition, the reputation of the military was largely based on battlefield successes, meaning imperial expansion boosted military prestige.

Economic Motivation

Industrial Japan also favored the expansion of the country’s empire because of the availability of raw materials. Japan established plantations in its colonial territories, such as those growing sugar in Taiwan, soybeans in Manchuria and rice in Korea. These commodities helped develop the commercial side of Japan’s economy through trading with the United States and Europe, although international trade would eventually draw Japan into World War II when the United States threatened to cut off oil supplies in 1941.