He retired in 1970, moved to Toronto in Canada, and began writing books on the history of the Israeli–Palestinian conflict, including Palestinian Rights and Losses in 1948 (1988) and Bitter Harvest: a Modern History of Palestine (1989).
1970 ging er in den Ruhestand, zog nach Toronto, wo er begann, Bücher über den israelisch-palästinensischen Konflikt zu verfassen, darunter Palestinian Rights and Losses in 1948 (1988) und Bitter Harvest: a Modern History of Palestine (1989).