Drawing on new archival findings, this article argues that shortly after the outbreak of the Second World War, Vladimir Jabotinsky, founder and leader of the right-wing Revisionist Zionist movement, had begun to advocate for the transfer of the Arab population from Palestine – an aspect of his thought previously unknown. Jabotinsky's support for population transfers runs counter to his lifelong political thought. Prior to the war, Jabotinsky was a staunch advocate of minority rights for Jews in Europe and for extensive autonomy for the Arab population in Palestine. This article argues that Jabotinsky's shift was a product of the war. Jabotinsky believed that millions of Jewish refugees would be prevented from returning to their pre-war homes in eastern Europe and would immigrate en masse to Palestine; to resettle these refugees, the Arab population, he argued, ‘would have to make room’. Attentively following debates on population transfers in Europe, Jabotinsky concluded that the era of minority rights had come to an end and envisioned an increasingly ethno-national Jewish state. By highlighting the eastern Europe context in Jabotinsky's thought, this article emphasizes the importance of studying the history of Zionism alongside the transformation of the nation-state in eastern Europe in the 1940s.