Which event did the Soviet Union fear during the Cold War

In the context of the Cold War, the world was bipolarized by the leadership of the US, capitalist and communist USSR. It was a dispute of hegemony, so the fear on both sides was to lose the leading role and see the economic model crumble. This is what happened to the USSR. A social and economic collapse of the USSR led to the end of the Cold War and the triumph of the capitalist model. Both sides also feared a warlike confrontation, so that the USSR could be destroyed if the capitalist nations contended for war.

(This is not my answer I found it by a verified user)