 Williamson was active in a wide variety of civic organizations, serving on the board of directors of the International Republican Institute; the board of the Committee in Support of Russian Civil Society; a member of the advisory committee for the International Human Rights Center at DePaul University, and a member of the Council on Foreign Relations.Williamson also was the Roberta Buffett Visiting Professor of International Studies at Northwestern University in Evanston, Illinois.Williamson authored seven books and edited three.