An analysis of how World War I affected the position of the Jews in the warring countries and their political self-perceptions. More precisely, it reviews the contest between Zionists and assimilationists in the broader framework of war, peace, and international diplomacy. He does so by considering the diplomatic endeavours of Lucien Wolf, who was an exponent of the Balfour Declaration and a co-architect of the Minorities Treaties that provided an internationally endorsed framework for Jewish existence in the Jew Europe after World War I. His analysis is of relevance to the contemporary discussion of Zionism as well as the to the problems of ethnic and religious minorities in Nation States. This book should interest scholars, students (undergraduate and graduate), and the general reader interested in Jewish and modern Europen history and politics, and the problems of ethnic and religious minorities in nation-states.