The 1890s witnessed Japan's first movements toward imperial conquest. The restoration of the Meiji royal dynasty in 1868 had launched Japan in a modern, industrialized direction and the leaders of the new Japan were keen to emulate the nations of Western Europe who ruled over colonies across the globe. The Sino-Japanese war of 1894-95 saw Japan defeat China in what was essentially a battle over the control of Korea. Japanese victory gave it control over the Korean peninsula (although this was not formally annexed until 1910), Taiwan and part of the Liaotung peninsula, which was later abandoned under international pressure. It also ensured that the powers of Europe and the United States would view Japan more seriously in future, says author Sarah Paine.
The same issues drove Japanese involvement in the Russo-Japanese war of 1904-05. The Japanese felt threatened by Russia and were anxious to ensure that Russia could not use the Korean peninsula as a jumping-off point to attack Japan itself. Japanese victory in this war secured the country's dominance in Korea but also gained a new sphere of influence in Manchuria in China, says author Susan Townsend.
Japan sided with the Allied Powers during World War I, a decision that allowed the country to gain territory in the Pacific at the expense of Germany. The German empire was divided by the Allied countries. Most of the affected territory was in Africa and was distributed to France and the United Kingdom, but Japan stood to gain in the Pacific. The islands of Micronesia had been under German control since 1889 but were officially transferred to Japan in October 1914. As a result of the war, Japan also gained the former German colony at Tsingtao on mainland China.
Japan took advantage of World War II to expand further south, occupying southern French Indochina in July 1941. In 1941 and 1942, the Japanese attacked and captured numerous other small Pacific and southeast Asian territories, including Singapore, Hong Kong, the Philippines, Burma, New Guinea and Borneo. In the later stages of the war, these territories, along with Japan's small rocky island possessions, became the venues for bloody battles such as Guadalcanal, Guam and Iwo Jima.
