Walter Ulbricht, the East German leader was one of a relatively tight-knit group of German communists who spent the war in Moscow, and then turned up in Germany at the end of April 1945 on a nation building mission, mandated by the Soviet leadership: Ulbricht would always remain close to Moscow. Current knowledge suggests that Stalin's mistrust of Paul Merker dated back at least to 1940, when Merker had shared with Comintern and German Communist party colleagues in Moscow criticism concerning the August 1939 Non-aggression pact between the Germans and the Soviets. It was an opinion he shared even more forcefully in the presence of Anton Ackermann, who later reported a 1939 meeting of the exiled German Communist Party that had taken place in Paris directly following announcement of the Nazi-Soviet pact, which Merker had characterized as an "unimaginably crass and shambolic anti-Soviet failing", in a peroration that had lasted for several minutes and which was felt to have "shown the true face" of Paul Merker. According to the historian Norman Naimark, Merker was by 1950 seen by the Soviets as an advocate for a more radical approach by the ruling SED (Party), and he was thought to be sympathetic with "sectarianist" former KPD (Communist party) members who had cooperated in the merger with the SPD only reluctantly, and many of whom still exercised significant influence at a regional and local level.