the most important articles for this paper. Leon was also instrumental in making contact with other sections of the Fourth International in wartime Europe – a most difficult and hazardous task; in August 1942, Leon co-organized the first meeting between the Belgian and French Trotskyist parties; he also led the illegal "party work among the proletarian soldiers of the Wehrmacht" and "attended meetings of the underground factory committees" at tremendous risk to himself. Leon exhorted Belgian workers to fight both Hitler and Churchill in the classical Leninist fashion of turning imperialist World War II into a civil war. Arrest, imprisonment, torture, and murder In 1943–1944, as the fascist regime of Benito Mussolini collapsed in Italy, the revolutionary socialist workers of Europe began to sense that the end of the war was near and that with it would come opportunities for revolutionary struggle – as had happened at the end of WWI. Leon, preparing for that eventuality, played a leading role "in the work of the European Conference of the Fourth International" held in February 1944. When news of the Allied landings in Europe reached him, Leon decided that the time had come, finally, when it would once again be safe for him to return to his home in Charleroi; but on the very night of his arrival his home was raided by the police and he was arrested. He was taken to prison and tortured by the Gestapo; yet even under these conditions Leon was able to smuggle letters from prison and establish a tenuous link with his Belgian party comrades. The Nazis wasted no time in deporting Leon to Auschwitz where he was brutalized until he became sick and was then selected by the SS to be sent to the gas chamber. He was thus murdered by the Nazis in September 1944 at the age of 26. Theoretical works Leon's most famous work in print is The Jewish Question: A Marxist Interpretation, a work which remains a widely used Marxist analysis of Jewish socio-economic history, antisemitism, and Zionism. Posthumously published in French in 1946, it dd not receive much attention on publication, but gained renewed interest in the late 1960s, and early 1970s as the aftermath of the Six Day War revived the relevance of Zionism and anti-Zionism on the political left, becoming the most influential text among critics of Zionism in the New Left. While containing a clear