The Cold War officially ended in 1991. This marked the dissolution of the Soviet Union, which had been a principal player in the ideological and geopolitical conflict that characterized the Cold War era, beginning after World War II. The end of the Cold War was signified by various events, including the fall of the Berlin Wall in 1989 and a series of treaties that reduced nuclear arsenals between the United States and the USSR. The conclusion of this era led to significant political changes and a new world order, shifting focus toward globalization.