After obtaining his diploma from the Geneva Graduate Institute in 1961, Cornelio Sommaruga served as a Swiss diplomat in The Hague, Rome, Geneva and Bern. From 1968 to 1973, he held several leadership positions as a Swiss representative to the European Free Trade Association (EFTA), to the United Nations Conference on Trade and Development, the General Agreement on Tariffs and Trade (GATT) and the United Nations Economic Commission for Europe (UN/ECE). He later returned to Bern where he held senior posts at the Office of Foreign Affairs of the Swiss government, including as Undersecretary of State at the Office of Foreign Economic Affairs from 1984 to 1987. He eventually left that position when he was nominated as President of the International Committee of the Red Cross (ICRC) in 1986. 

During his tenure at the ICRC, Sommaruga was known for not shying away from taking strong stances, particularly on behalf of victims of armed conflict, and in defence of the laws and principles that protect them. Most notably, he was the first ICRC President to publicly acknowledge the organisation’s failure to provide meaningful assistance and protection to Jews during World War II. This public declaration first took the form of a postface he signed for Jean-Claude Favez’s book Une mission impossible? Le CICR, les déportations et les camps de concentration Nazis, published in 1989. He later found an occasion, on the 50th anniversary of Auschwitz’s liberation, to publicly reiterate his stance at a conference that gathered heads of states whose citizens had been interned in the death camp. It is this constant and rigorous defence of international humanitarian law that also led him to take an openly strong position against anti-personnel mines and blinding weapons. He notably called upon the international community to recognise the danger and the atrocity of the indiscriminate use of landmines during a speech at the ICRC in 1993. His efforts ultimately helped member states adopt the Ottawa Treaty in 1997, which bans antipersonnel landmines. 

His exceptional career earned him numerous awards and honorary distinctions, and he did not cease contributing to the wellbeing of the international community in his retirement, serving as chair of Initiatives of Change and of the Geneva International Centre for Humanitarian Demining (GICHD), based in the Maison de la paix. He remained an active member of the Geneva Graduate Institute’s community, as well. He was a member of the foundation board from 2000-2004 and served as ad interim president in 2003.