(VKP(b)). He was exiled to Alma-Ata (now Almaty) in January 1928 and then expelled from the USSR in February 1929. As the head of the Fourth International, Trotsky continued in exile to oppose what he termed the degenerated workers' state in the USSR. On 20 August 1940, Trotsky was attacked in Mexico City by Ramón Mercader,