Brian joined Crisis Group in June 2021 as Senior Adviser for the U.S. Program. He focuses on developing policies and institutional checks to decrease U.S. reliance on military tools in foreign affairs, including through legislative reforms of war powers and counterterrorism authorities. 

Prior to joining Crisis Group, he worked for a decade in the Office of the Legal Adviser at the U.S. Department of State where he advised the U.S. government on legal and policy issues relating to counterterrorism, the use of military force, and partnered military operations.

Brian holds a B.A. in anthropology from Cornell University, a DPhil from Oxford University and a J.D. from Yale University.