Even though the war was fought physically or mentally it lasted decades. The cold war started after WWII around 1947. The marshall plan was introduced by the U.S. This plan would allow U.S. to aid Europe back to a stable government but would include control of Eastern Europe that was controlled and ruled by communism by Soviet Union. Soviet Union rejected the plan and started another plan. Soviet Union also built a wall between east Europe and western Europe called the Iron curtain. This enabled and helped to keep communism in Europe. The arguing over the Marshall plan caused much tension between these two nations aiding to another cause of the cold war.
In 1949 the Soviet Union detonated their first atomic bomb, and the U.S. joined the North Atlantic Treaty Organization in alliance with Canada, Great Britain, France, Portugal, Norway, Belgium, Iceland, Gutenberg, the Netherlands, and Italy. In 1955 Soviet Union started the Warsaw Pacts making alliances with Yugoslavia, Albania, East Germany,Bulgaria, Czechoslovakia, Poland, and Romania. This continued the coldwar by causing more tensions between the nations.
Finally, the cold war between the united states and the soviet union started to end with the agreement to hold back their nuclear arms race in the 1980s.The final end to the war wasn't until 1991 when the soviet union was dissolved.