World War I

World War I began in 1914. Japan, as an ally of Britain, at once declared war on Germany. The war gave Japan an opportunity to enlarge its empire slightly. More important, the war gave Japan an economic advantage in India and the rest of Asia.

As Western nations became preoccupied with the war in Europe, they stopped their investment and trade in the East. Japanese exporters and manufacturers took that opportunity to move into Indian and other Asian markets. The zaibatsu expanded, and Japan's economy boomed.