Law clerk United States District Court, 1955-1956. Associate, then partner Morgan, Lewis & Bockius, Philadelphia, 1956-1968, 72-73. Principal deputy assistant secretary international security affairs United States Department Defense, Washington, 1968-1969.
Defense advisor United States mission to North Atlantic Treaty Organization, 1969-1972. Representative to Strategic Arms Limitation Talks II United States Arms Control/Disarmament Agency (Arms Control and Disarmament Agency), 1973-1977, ambassdor, alternate chairman United States del, 1977-1978, chairman, 1978-1980, special representative for arms control and disarmament negotiations, 1977-1980, director, 1980-1981. Associate Center for Foreign Policy Development, Brown University, Providence, 1981-1982.
Partner Earle and Greene & Company, Stamford, Connecticut, 1982-1983, Baker & Daniels, Washington, 1983-1986. National policy director Lawyers Alliance for World Security, 1987-1990, chairman, board directors, 1990-1994. Deputy director Arms Control & Disarmament Agency, 1994-1999.
Visiting professor Indiana University Law School, 1994.
Served with Army of the United States, 1950-1952. Member American Law Institute, Council Foreign Relations, International Institute Strategic Studies, Philadelphia Club, Metropolitan Club (Washington), Harvard Club (president Philadelphia club 1967-1968), Brook Club (New York City), Rockaway Hunting Club (Long Island), Lawrence Beach (Long Island) Club.