Soviet Union–United States relations

Relations between the Soviet Union and the United States were fully established from 1933 until 1991 as the succeeding bilateral ties to those between the Russian Empire and the United States, which lasted from 1809 until 1917; they were also the predecessor to the current bilateral ties between the Russian Federation and the United States that began in 1991 after the end of the Cold War.

The relationship between the Soviet Union and the United States was largely defined by mistrust and hostility. The invasion of the Soviet Union by Germany as well as the attack on the U.S. Pacific Fleet at Pearl Harbor by Imperial Japan marked the Soviet and American entries into World War II on the side of the Allies in June and December 1941, respectively. As the Soviet–American alliance against the Axis came to an end following the Allied victory in 1945, the first signs of post-war mistrust and hostility began to immediately appear between the two countries, as the Soviet Union militarily occupied Eastern European countries and turned them into satellite states, forming the Eastern Bloc. These bilateral tensions escalated into the Cold War after the creation of the entire Korean Peninsula divided into Soviet-backed North Korea and the US-backed South Korea as one of the earliest flashpoints in 1948 that led to the Korean War for over three years from 1950 to 1953 where the conflict had never technically ended, a decades-long period of tense hostile relations with short phases of détente that ended after the collapse of the Soviet Union and emergence of the present-day Russia at the end of 1991.