The SPD now was in the opposition regarding the domestic agenda of the new government while supporting its foreign policy, in particular regarding reparations to the Allies. Müller was an early advocate of joining the League of Nations and of moving politically closer to the West. He was critical of the Soviet Union's authoritarian system of government, its revolutionary goals and its support for the radical left in Germany. However, he opposed a blockade of the Soviet Union by the western Allies.