Steven R. Ratner is the Bruno Simma Collegiate Professor of Law at the University of Michigan. He teaches and writes in the field of public international law on a range of issues, including state and corporate duties regarding foreign investment, territorial and ethnic-based disputes, civil and interstate armed conflict, and accountability for human rights violations. He is also interested in the intersection of international law and political philosophy and other theoretical issues.

Ratner came to the Law School in 2004 from the University of Texas School of Law. A member of the board of editors of the American Journal of International Law from 1998 to 2008, he began his legal career as an attorney-adviser in the Office of the Legal Adviser at the US State Department.

In 1998–1999, the United Nations (UN) secretary-general appointed him to a three-person group of experts to consider options for bringing the Khmer Rouge to justice. And in 2010–2011, he was a member of the UN’s three-person Panel of Experts on Accountability in Sri Lanka, which advised the secretary-general on human rights violations related to the end of the Sri Lankan civil war. Since 2022, he has been a commissioner on the UN Human Rights Council’s three-person International Commission of Human Rights Experts on Ethiopia.

Ratner also worked in the legal division of the International Committee of the Red Cross in Geneva and at the Office of the High Commissioner on National Minorities of the Organization for Security and Cooperation in Europe in The Hague. From 2009 to 2021, he was a member of the State Department’s Advisory Committee on International Law. He also is a counsellor of the American Society of International Law and a member of the American Law Institute. He has served as an expert on international investment law in various arbitrations and established. At the Law School, he directs the Geneva International Fellows Program.