Professor McGuinness joined the faculty in 2003 after practicing law in the litigation department of Paul, Weiss, Rifkind, Wharton & Garrison LLP in New York.
While at law school, Professor McGuinness was an articles editor for the Stanford Law Review and a graduate fellow at the Stanford Center on Conflict and Negotiation. Following law school, she clerked for Judge Colleen McMahon, of the U.S. Southern District of New York.
Prior to law school, Professor McGuinness was a Foreign Service Officer with the State Department. She was a Special Assistant to Secretary of State Warren Christopher from 1993-1994. Professor McGuinness teaches international law, international human rights, international business transactions, foreign affairs and the constitution, and federal courts. She has published in the area of mediation in armed conflict, the status of refugees in conflict zones, and the role of the UN in war.
Professor McGuinness is a co-founder of, and contributor to, Opinio Juris, a weblog dedicated to reports, commentary, and debate on current developments and scholarship in the fields of international law and politics.