<human>:  What role did the Soviet Union play in the Cold War?
<bot>: The Soviet Union played a major role in the Cold War by supplying military and economic resources to its satellite states, supporting major communist revolutions around the world, and maintaining a vast nuclear arsenal that posed a significant threat to the Western allies. Additionally, their hardline stance on ideological differences provided a stark contrast to the West and the ensuing superpower tensions created the conditions of the Cold War.