For the next twelve years he directed the UN refugee agency through one of its most difficult periods, coordinating the international response to the 1971 Bangladesh crisis that uprooted 10 million people, the 1972 exodus of hundreds of thousands of Hutus from Burundi to Tanzania, and the Vietnamese boat people tragedy of the mid-1970s.
Selama dua belas tahun berikutnya, ia memimpin agensi pengungsi PBB melalui salah satu periode tersulitnya, mengurusi tanggapan internasional terhadap krisis Bangladesh 1971 yang menimpa 10 juta orang, eksodus 1972 ratusan ribu Hutu dari Burundi ke Tanzania, dan tragedi orang perahu Vietnam pada pertengahan 1970an.