At the end of turn of the twentieth century, after decisive victories over the crumbling Chinese and Russian empires in warfare in the Eastern Pacific, Japan was an ascendant world power intent on dominating Asia. The Japanese emperor had recently been restored to head of the modern state, and a parliament formed after centuries of military feudalism and isolation. Japan wanted to catch up with the industrialized West and did so very quickly, borrowing from the German model. With their newfound technological and productive capacities, traditionally inward-looking Japan set its sights on establishing its own naval empire, just as the United States was also emerging as a a rival to Japan with its control of the Philippines, Guam, and trade concessions with Qing China.
As a growing island nation with limited resources and a limited labor force, Japan needed to expand its food and raw material supply as well as its workforce, since all able-bodied Japanese men were expected to serve in the military. With its presence already established in Northeastern China, the Japanese military annexed the Korean peninsula, whose people the Japanese believed to be inferior. For decades of occupation until the end of World War II, Japan extracted food, materials, and labor from the the Koreans, even enslaving young women for sexual service to the Japanese military.
With the Russian and Chinese states collapsing during World War II, Japan became the stand-alone regional power, though it was not yet confident enough to directly challenge the Western forces on their doorstep. With increasing audacity, Japan flexed its might in the absence of significant resistance by invading China through Manchuria in the early 1930s, unleashing a brutal occupation of the Chinese mainland and Taiwan, which resulted in the deaths of hundreds of thousands of Chinese civilians through murder and deprivation. With so much territory secured in Asia, Japan was able to construct a series of air and naval stations on strategic islands dotting the Pacific and Indian Oceans. With their military machine at full strength, Japan was now a serious threat to Australia, a British commonwealth, and to the Pacific territories of the US.
The Japanese attack on the American fleet at Pearl Harbor in Hawaii, as the ultimate expression of Japanese imperial self-confidence and hubris, also proved to be its most consequential. Drawing the fiercely isolationist US into war with Japan, key victories in bloody Pacific naval campaigns eventually turned the tide against Japan. Despite the decimation of their forces, the Japanese empire would not surrender, and so the US considered a full-scale invasion of Japan the only way to end the fighting. Projections about the destructive costs of a land invasion for both sides were analyzed by the American government, and the astronomical predictions led to the development of the atomic bomb as a more humane alternative. In August of 1945, the Japanese Empire became the only victim of an offensive nuclear weapon twice over, as the US bombings finally caused the Japanese to surrender. In the many decades since the end of World War II, Japan has been demilitarized and has sought to make amends and seek forgiveness for its historic atrocities.