Early in his political career, Piłsudski became a leader of the Polish Socialist Party. Concluding that Poland's independence would have to be won by force of arms, he created the Polish Legions. In 1914 he anticipated the outbreak of a European war, the Russian Empire's defeat by the Central Powers, and the Central Powers' defeat by the western powers. When World War I broke out, he and his Legions fought under Austrian army control against Russia. In 1917, with Russia faring badly in the war, he withdrew his support from the Central Powers and was arrested by the Germans.