[6] Prior to his arrival at George Washington University Law School in 1998, Murphy was the legal counselor at the Embassy of the United States, The Hague from 1995 to 1998; in this position, he argued several cases before the International Court of Justice (ICJ) and represented the U.S. government in matters before the International Criminal Tribunal for the former Yugoslavia.
In addition to his academic appointment, he frequently serves as counsel, expert, or arbitrator in various fora, such as in cases before the ICJ;[7] International Centre for the Settlement of Investment Disputes (ICSID) and the Permanent Court of Arbitration; and as ad hoc judge at the International Tribunal for the Law of the Sea.
In 2022, Murphy was appointed by the President of the World Bank to chair a Court of Arbitration between Pakistan and India concerning the Indus Waters Treaty.
In 2023, he was appointed as an arbitrator for a NAFTA-related dispute brought by the Alberta Petroleum Marketing Commission against the United States concerning the Keystone XL pipeline.
from the University of Virginia School of Law (1995; Ford Foundation Graduate Scholarship and Council on Foreign Relations Fellow), his LL.M.