Politcal Officer in the United Nations Secretariat in New York from 1949.

Principal Secretary, UN Special Committee against Apartheid, 1963-67, and Chief of Section for African Questions, 1967-1975.

Director, UN Centre against Apartheid, 1976-1984.

Assistant Secretary-General, UN, 1983-1985.

Since retirement, engaged in research and writing, especially on the liberation struggle in South Africa, on the United Nations and on Mahatma Gandhi. Edited speeches of Krishna Menon (Chairman of the Indian Delegation) at the United Nations, and speeches and articles by Olof Palme (Prime Minister of Sweden).