Paul R. Williams holds the Rebecca I. Grazier Professorship in Law and International Relations at American University. Professor Williams teaches at the School of International Service and the Washington College of Law and also directs the joint JD/MA program in International Relations. Professor Williams is co-founder of the Public International Law & Policy Group (PILPG), a non-profit group, which provides pro bono legal assistance to states and governments involved in peace negotiations, post-conflict constitution drafting, and war crimes prosecutions.

Over the course of his legal practice, Professor Williams has assisted over two dozen peace negotiations and post conflict constitutions. Professor Williams has advised governments across Europe, Asia, as well as North and Sub-Saharan Africa on state recognition, self-determination and state succession issues, and on drafting and implementation of post-conflict constitutions. He is a leading scholar on peace negotiations and post-conflict constitutions, and a highly sought-after international law and policy analyst, being interviewed on over 500 occasions by major media outlets including The New York Times, U.S. News and World Report, BBC, and CNN. Professor Williams has authored five books on a variety of topics such as international human rights, international environmental law and international norms of justice; he has also written over three dozen articles on a wide variety of public international law topics. Additionally, Professor Williams has testified before congressional committees concerning peace strategy in Kosovo, and holding war criminals accountable.

Prior to his arrival at American University, Professor Williams spent time as a Senior Associate with the Carnegie Endowment for International Peace, and as a Fulbright Research Scholar at the University of Cambridge. Professor Williams also served as an Attorney-adviser for European and Canadian affairs at the U.S. Department of State, Office of the Legal Adviser.