The Cold War was a geopolitical, ideological and economic struggle between the two greatest world powers, the US and the USSR, former allies in WWII, and lasted from 1947 to 1991. It started because the USSR imposed a communist regime on the countries of Eastern Europe. The US and its allies were feared of the expansion of the USSR's power and the spread of communism, so America's response was the Marshall Plan. The official policy of US became containment of communism.
