Reception and Instrumentalization of the Balfour Declaration among Jews, 1917-1937 The Balfour Declaration was hailed by many Jews as a definitive recognition of the national solidarity of the Jewish people and, in popular understandings, its right to establish sovereignty over Palestine; but Britain’s pledge of support to Zionist Jews also provoked protests from important sections of Jewry in the U.K. and elsewhere. While scholarship has examined in detail the origins of the Declaration, less well-studied aspects of the Declaration are its reception and interpretation over time, especially its instrumentalization in intra-Zionist polemics. The paper analyzes reception of the Balfour Declaration among Jews of various ideologies and regions, 1917-1937, focusing on the large, influential, and free-spoken Diaspora communities in Germany and the U.S. Four sets of research questions are pursued. (1) What were the immediate reactions of Jews to the Declaration, in 1917? What factors (geographical, political, religious, ideological, etc.) influenced these reactions? (2) In the two decades after 1917, how was the Declaration commemorated, and what was its place within the historiography of Zionism? (3) How was the Declaration deployed in intra-Zionist debates? (4) In Jewish and Zionist thinking in the two decades after its issuance, what were the obstacles causing “delay” in the Declaration’s implementation? Documentation of the study rests on the German-Jewish periodical press, e.g., Palästina, Allgemeine Zeitung des Judentums, Menorah, with special attention to a major essay in Der Morgen, “Juden und Araber in Palästina” (1929). Other sources include mainstream and Jewish sections of the U.S. press; archives of the American Jewish Committee; Palestine Bulletin/Palestine Post; and documents from the British National Archives. The paper documents the spectrum of Jewish reaction to the Declaration, from enthusiastic endorsement, to qualified approval, to categorical rejection and hostility. Negative reactions in Germany were influenced by the war with Britain, but also by contrasting conceptions of Jewish identity; there were also approving responses among German Jews. U.S. Jews’ reactions exhibit the same diversity. Although commemorations took place, little ceremony attended “Balfour Day”; but the Declaration was a historiographical watershed, consistently articulated to the 1897 Zionist Congress. In intra-Zionist controversies, loyalty to the Declaration became a shibboleth. But Jews’ failure to respond in terms of immediate large-scale immigration and funding for colonization made an aggressive implementation impossible, and critics from within Zionist circles argued that misapprehensions of the Declaration’s meaning, fostered by Zionist propagandists, had exacerbated relations with the Arabs.