Japan (Japanese: 日本, Nihon), formally referred to as the Empire of Japan (大日本帝國, Dai Nihon Teikoku), is a predominantly insular nation located in East Asia. The nation is comprised of five main islands (Hokkaido, Honshu, Kyushu, Shikoku, and Takasago), several smaller archipelagos (the Bonin Islands, the Caroline Islands, the Kuril Islands, the Mariana Islands, the Marshall Islands, and the Ryukyu Islands), and the southeastern most portions of the Korean Peninsula.
The contemporary history of Japan began during the late 19th Century and the Meiji Restoration, which was in response to the growing dominance of European powers in East Asia. It was during this period that Japan began to modernize themselves into a nation state. By the beginning of the 20th Century, the Empire of Japan had emerged as a native Great Power within Asia. This early period of national enthusiasm came to an end in 1905, when they were defeated by the Russian Empire during the Russo-Japanese War.
The early 20th Century would be a period in which the Empire of Japan began to re-establish their regional prestige. Japanese troops would be redeployed to the Russian Far East following the Russian Revolution. Despite their reassertion in the area, Japan would gradually adopt a far less confrontational foreign policy (compared to previous governments). With the growth of China and the Soviet Union, Japan moved to further solidify their alliance with the United Kingdom.
From the start of World War II, Japan declared their early support for the Allied Powers and agreed to send a small number of troops to fight alongside the United Kingdom. Though their early involvement was strictly in accordance with their alliance with the UK, the war would soon turn global as the Republic of China forms an alliance with Germany and Italy. Within the first few years of the war, Chinese forces have seized most of Indochina and occupied the colonies of the Pearl River Delta. Following China's invasion of Japanese Korea in late 1941, all Japanese involvement in Europe ceased in order to defend the Home Islands.
Despite the dominance of the Chinese Army, the Japanese Navy was far superior and quickly took advantage of China's lifeline (via German aid). A series of amphibious invasions soon took place against the Chinese mainland, with Japanese-controlled Korea and Takasago serving as launching points. With the European war coming to an end in May 1945, Japanese troops in China would soon be joined by American, British, and Soviet forces. Despite the loss of their ally, Chinese forces would continue to fight on. Fearing a prolonged guerrilla war, the United States detonated the first two atomic bombs on China. Days later, Chinese forces surrendered to the Japanese. The Empire of Japan emerges as a Great Power following the war and would play a role in the establishment of the United Nations.
With the beginning of the Cold War and the new dominance of the Soviet Union and the United States, Japan's placement in this new world order initially remained uncertain. The newly militarized and nationalist government was strongly opposed to the expansion of communism, but was also very opposed to the re-establishment of European domination in Asia. The Greater East Asia Co-Prosperity Sphere (GEACPS) would be established as a counterbalance against American and Soviet domination. By the 1950s, Japan had successfully detonated their first atomic bomb, becoming the only Asian power to possess such weapons. Japanese co-operation with with West came into question during the Alaskan Missile Crisis, during which Japan support Soviet efforts to remove American missiles from Alaska (which Japan feared could be used against them). As part of the decolonization of Asia, Japan increasingly began to support pro-Tokyo government in French Indochina and much of the Dutch East Indies.
Relations between Japan and the West began to improve as the Cold War progressed. This would become more apparent as Japanese troops would be deployed against communist rebels in Borneo, China, and Vietnam. It was also during this time that the national economy of Japan began to increase at an exponential rate, soon to become the second-largest economy (after the United States). Technological advancement would also increase, reaching its apex during the 1970s with the successful launch of Japanese astronauts (eliminating the duopoly once held by the Soviet Union and the United States).
By the late 1980s, the situation in Japan began to chance for the worst. Decades of military domination, economic decline, ethnic tensions, the death of the Emperor, the end of the Cold War, and the dissolution of the Soviet Union would culminate to spur change. The first truly democratic elections were held in the early 1990s. Among the key issues of the new government was the future of Korea, which had overwhelmingly voted in pro-independence parties. The National Diet would agree to hold an independence referendum for Korea. With the exception of the Kyoshodo region in southeastern Korea, the majority voted in favor of independence. Within a year, the Republic of Korea is established. Despite international opposition Japan retained Korean prefectures which had voted to remain within Japan, allowing the pro-Japanese Kyoshodo region to remain within the Empire.