Reagan met four times with Soviet leader Mikhail Gorbachev, who ascended to power in 1985, and their summit conferences led to the signing of the Intermediate-Range Nuclear Forces Treaty. Gorbachev tried to save Communism in the Soviet Union first by ending the expensive arms race with America, then by shedding the East European empire in 1989. The Soviet Union collapsed on Christmas Day 1991, ending the U.S–Soviet Cold War.