The document summarizes the end of the Cold War between the USSR and the United States in the late 1980s and early 1990s. It describes how the USSR weakened economically and politically under the leadership of Mikhail Gorbachev, who implemented reforms of glasnost and perestroika. It then discusses how Gorbachev allowed countries of the Warsaw Pact to set their own paths, leading to the fall of communist governments across Eastern Europe in 1989, including the tearing down of the Berlin Wall. Finally, it notes the dissolution of the USSR itself in 1991, marking the official end of the Cold War.