Professor Allen joined the UW School of Law and School of Marine Affairs faculties in 1996, following his retirement from the U.S. Coast Guard. He was the Honor Graduate in his law school class and served as Editor-in-Chief of the Washington Law Review. At graduation he received the Vivian Carkeek Prize for legal writing and was inducted into the Order of the Coif and the National Order of Barristers. He was later admitted to practice in Oregon and Washington, the Court of International Trade, the Ninth and Federal Circuits, the Department of Veterans Affairs, and the U.S. Supreme Court. He is a fellow in the Nautical Institute and the Royal Institute of Navigation and a member of the Maritime Law Association. In 2016 Secretary of Homeland Security Jeh Johnson appointed Professor Allen to the Department's National Maritime Security Advisory Committee.
Professor Allen's teaching and research interests include maritime and international law, national and homeland security law and Arctic law and policy. He is on the Board of Editors of Ocean Development and International Law and the Journal of Navigation, the Board of Advisors of the Naval War College's International Law Studies and authored International Law for Seagoing Officers (6th ed. 2014), Maritime Counterproliferation Operations and the Rule of Law (2007), and Farwell's Rules of the Nautical Road (8th ed. 2005).
Professor Allen has been honored by the students three times with the Professor of the Year Award. In 2003 he was named a Washington Law Foundation Scholar, and in 2005 he was appointed the Judson Falknor Professor of Law. In 2006, the members of the Washington Law Review honored Professor Allen with their Distinguished Alumni Award.
During the 2011-2012 academic year, Professor Allen served as a Visiting Professor at Yale Law School and as the Distinguished Visiting Professor of Maritime Studies at the U.S. Coast Guard Academy. During the 2006-07 academic year he held the Charles H. Stockton Chair in International Law at the U.S. Naval War College in Newport, RI.