Parti ouvrier polonais
After the German invasion of the Soviet Union in 1941, Berman escaped to Moscow. Later he became an instructor at the Comintern school in Kushnarenkovo near Ufa, where he trained displaced Polish communists, activists for the new Soviet-sponsored Polish Workers' Party (PPR). With the help from Georgi Dimitrov and Jerzy Borejsza, Berman was able to bring there his wife and daughter Lucyna.