throughout the summer of 1928 and was determined to modernize his armed forces. From 1929 onwards, therefore, the Communists voted faithfully with the far right DNVP and Hitler's NSDAP in the Reichstag despite fighting them in the streets. Relying on the foreign affairs doctrine pursued by the Soviet leadership in the 1920s, in his report of the Central Committee to the Congress of the All-Union Communist Party (b) on June 27, 1930, Joseph Stalin welcomed the international destabilization and rise of political extremism among the capitalist powers. Early 1930s The most intensive period of Soviet military collaboration with Weimar Germany was 1930–1932. On June 24, 1931, an extension of the 1926 Berlin Treaty was signed, though it was not until 1933 that it was ratified by the Reichstag due to internal political struggles. Some Soviet mistrust arose during the Lausanne Conference of 1932, when it was rumored that German Chancellor Franz von Papen had offered French Prime Minister Édouard Herriot a military alliance. The Soviets were also quick to develop their own relations with France and its main ally, Poland. This culminated in the conclusion of the Soviet-Polish Non-Aggression Pact on July 25, 1932, and the Soviet-French non-aggression pact on November 29, 1932. The conflict between the Communist Party of Germany and the Social Democratic Party of Germany fundamentally contributed to the demise of the Weimar Republic. It is, however, disputed whether Hitler's seizure of power came as a surprise to the USSR. Some authors claim that Stalin deliberately aided Hitler's rise by directing the policy of the Communist Party of Germany on a suicidal course in order to foster an inter-imperialist war, a theory dismissed by many others. During this period, trade between Germany and the Soviet Union declined as the more isolationist Stalinist regime asserted its power and as the abandonment of post-World War I military control decreased Germany's reliance on Soviet imports, such that Soviet imports fell to by 1934. Persecution of ethnic Germans in the Soviet Union The USSR had a large population of ethnic Germans, especially in the Volga German Autonomous Soviet Socialist Republic, who were distrusted and persecuted by Stalin 1928 to 1948. They were relatively well-educated, and at first, class factors played a major role, giving way after 1933 to ethnic links to the dreaded Nazi German regime as the chief criterion. Taxes escalated after the Operation Barbarossa. Some settlements were permanently banished