The Soviet Union, officially the Union of Soviet Sovereign Republics (Russian: Союз Советских Cуверенных Республик/Soyuz Sovyetskikh Suvyeryennykh Ryespublik) or USSR (CCCP), and occasionally Russia, is a nation in northern Eurasia and the largest nation on Earth, spanning the entire north of the Asian continent, with coasts on both the Pacific and Arctic Oceans. The Soviet Union shares borders with Korea, China, Mongolia, Georgia and Persia to the south, and Finland, Baltica, Poland, Romania, and Armenia to the west, as well as maritime borders to the east with Japan's Karafuto Prefecture across the Tartar Strait and Canada's Yukon Province across the Bering Strait.
The nation has a long and turbulent history of warfare that began with Mongol invasions in the 13th century (around 1237 AD), the beginning of the reign of the Tsars in the 16th century, followed by the birth of the Russian Empire in 1721. Next came World War I and the October Revolution in the early 20th century, the inception of the Soviet era in 1922, a costly victory in World War II (in which over 23 million Russian soldiers and civilians died; roughly 14% of the national population at the time), minor involvement in Korea and the Sumatra, and most notably the Cold War with the United States from 1948 to 1995.
The Cold War brought about much Russian technological innovation throughout the last half of the 20th century, including the first artificial orbital satellite (Sputnik 1) in 1957, Yuri Gagarin's first human flight into space in 1961, establishment of the Baikonur Cosmodrome in Kazahkstan, the Salyut series of space stations, and the current Mir Space Station (launched in 1986) and the Buran space shuttle, both of which are key to maintaining the USSR's presence in orbit. And since the mid-1970s, the United States and the USSR have been increasingly cooperative in spaceflight, beginning with the joint Apollo-Soyuz mission in 1975, and continuing with the current Shuttle-Buran and Shuttle/Mir programs.
In 1989, a series of revolutions in Eastern Europe saw the collapse of the Warsaw Pact and the independence of these nations (including the reunification of East and West Germany and the tearing-down of the Berlin Wall). These events were followed by a major reformation of the Soviet government with the signing of the New Union Treaty on August 20, 1991, in which the government was de-centralized and the constituent republics reorganized into a new federation. While the Cold War was now unofficially over, tensions between the USSR and the United States would continue until 1995, when the Cold War was officially ended via the Warsaw Accords. As a result, the world's two superpowers are much closer today than ever before, but even in this new era of cooperation, they still continue to compete for influence on the global stage.
Russian Empire (1721-1917)
World War I/October Revolution (1914-1917)
Soviet Era (1922-present)
World War II (1938-1945)
Main Article: World War II (1938-1945)
Warsaw Pact Revolutions (1989)
Soviet Reformation (1991)
Main Article: New Union Treaty (1991)
Modern Times (1991-Present)
Main Article: Republics of the Soviet Union