In 1940, shortly after the outbreak of World War II, he published a book-length study which argued for the incompatibility of Nazism and Islamic tradition. The work, entitled The Islamic Traditions and the Nazi Principles: Can They Agree? was simultaneously published in Beirut and Cairo. Together with the strain in his personal relations with the leader of the Syrian Communist Party, Khalid Bakdash, the publication led to his expulsion from the Communist Party,[29] which regarded the work's dependence on many Islamic texts as contrary to the secularist principles of Marxism.[5] In the postwar period he enjoyed a successful career as a literary critic and broadcaster in both Lebanon and Cyprus.[29] He had a son, and one of his daughters became a prominent doctor in the Soviet Union.[19] A literary prize in his honour, the Najati Sidqi Competition, has been held in Ramallah.[30] Sidqi died in exile in Athens in 1979.[31]