Office that Soviet Russia wanted "a common frontier with Germany, south of Lithuania, approximately on a line with Białystok". In other words, Poland was to be partitioned once again. These promptings were repeated over the years, with the Soviets always anxious to stress that ideological differences between the two governments were of no account; all that mattered was that the two countries were pursuing the same foreign policy objectives. On December 4, 1924, Victor Kopp, worried that the expected admission of Germany to the League of Nations (Germany was finally admitted to the League in 1926) was an anti-Soviet move, offered German Ambassador Ulrich Graf von Brockdorff-Rantzau to cooperate against the Second Polish Republic, and secret negotiations were sanctioned. However, the Weimar Republic rejected any venture into war. Diplomatic relations By 1919, both Germany and Russia were pariah nations in the eyes of democratic leaders. Both were excluded from major conferences and were deeply distrusted. The effect was to bring Moscow and Berlin closer together, most notably at Rapallo. German diplomats worried at the revolutionary nature of the Soviet Union, but were reassured by Lenin's New Economic Policy that seem to restore a semblance of capitalism. Berlin officials concluded that their policy of engagement was a success. However, 1927 Berlin realized that the Comintern, and Stalin, did not reflect a retreat from revolutionary Marxist–Leninism. In 1925, Germany broke its diplomatic isolation and took part in the Locarno Treaties with France and Belgium, undertaking not to attack them. The Soviet Union saw western European détente as potentially deepening its own political isolation in Europe, in particular by diminishing Soviet-German relationships. As Germany became less dependent on the Soviet Union, it became more unwilling to tolerate subversive Comintern interference: in 1925, several members of Rote Hilfe, a Communist Party organization, were tried for treason in Leipzig in what was known as the Cheka Trial. On April 24, 1926, Weimar Germany and the Soviet Union concluded another treaty (Treaty of Berlin (1926)), declaring the parties' adherence to the Treaty of Rapallo and neutrality for five years. The treaty was signed by German Foreign Minister Gustav Stresemann and Soviet ambassador Nikolay Krestinsky. The treaty was perceived as an imminent threat by Poland (which contributed to the success of the May Coup in Warsaw), and with caution by other European states regarding its possible effect upon Germany's obligations as a party to the Locarno Agreements.