For 10 points, identify this Russian revolutionary who was killed with an ice axe in 1940 by Ramon Mercader while living in exile in Mexico.
This man founded the movement named Fourth International, and he was the leader of the Soviet delegation for the negotiations of the Treaty of Brest-Litovsk.  Born Lev Davidovich Bronstein, he was second in command to Vladimir Lenin during the October Revolution. After Lenin's death, he was expelled from the Communist Party for his opposition to Joseph Stalin and later deported from the Soviet Union. For 10 points, identify this Russian revolutionary who was killed with an ice axe in 1940 by Ramon Mercader while living in exile in Mexico.
This man founded the movement named Fourth International, and he was the leader of the Soviet delegation for the negotiations of the Treaty of Brest-Litovsk.  
Leon {Trotsky} [accept Lev Davidovich {Bronstein} before mentioned]