- Planning Director, United States Studies Centre, University of Sydney (from 2006 to 2007)
- Director, Lowy Institute for International Policy, Sydney (from 2003)
- Deputy Chairman of Board, Graduate School of Government, University of Sydney (from 2003 to 2005)
- Emeritus Fellow, All Souls College (from 2001)
- Chairman of the Council, Australian Strategic Policy Institute, Canberra (from 2000 to 2005)
- Chichele Professor of the History of War and Fellow, All Souls College; co-director All Souls Foreign Policy Studies Programme (from 1987 to 2001)
- Director, International Institute of Strategic Studies, London (from 1982 to 1987)
- Official Australian Historian for the Korean War (from 1969 to 1982)
- Senior Fellow, International Relations (till 1977), Professorial Fellow (from 1977); also (from 1971) Head, Strategic and Defence Studies Centre, Australian National University (from 1969 to 1982)
- Served in Australian Army; war service in Vietnam 1966-67, mentioned-in-dispatches (from 1955 to 1968)
- Undergraduate and Postgraduate, Brasenose College, Oxford, MA, D. Phil (from 1961 to 1965)
- Undergraduate, University of Melbourne, BE and Rhodes Scholar for Victoria (from 1959 to 1960)
- Royal Military College of Australia (from 1955 to 1958)
- International relations
- The history of war
- (ed. with John Baylis), Alternative Nuclear Futures (New York: Oxford University Press, 2000).
- (joint editor), War, Strategy and International Politics (Oxford: Clarendon Press, 1992).
- Australia in the Korean War 1950–53, 2 vols (Australian War Memorial, 1981 and 1985).
- General Giap – Politician and Strategist (New York: Praeger, 1969).
- Vietnam Task: The 5th Battalion, the Royal Australian Regiment, 1966-67 (Melbourne: Cassell Australia, 1968).
- The German Army and the Nazi Party, 1933–1939 (Melbourne: Cassell, 1966).
- Foundation Fellow of the Australian Institute of International Affairs (2008)
- Chairman of Trustees, Imperial War Museum (from 1998 to 2001)
- Chairman, Council, IISS (from 1996 to 2001)
- Member, Rhodes Trust (from 1995 to 2001)
- Member, Canberra Commission on the Elimination of Nuclear Weapons (from 1995 to 1997)
- Governor, Salzburg Seminar (from 1992 to 1997)
- Trustee, Commonwealth War Graves Commission (from 1991 to 2001)
- Chairman, Management Committee, Sir Robert Menzies Centre for Australian Studies, University of London (from 1990 to 1995)
- Chairman of Board, Centre for Defence Studies, Kings College London (from 1990 to 1995)
- Governor, International Peace Academy (from 1990 to 2001)
- Trustee, Imperial War Museum (from 1990 to 1998)
- Governor, Ditchley Foundation (from 1989 to 2001)
- Armed Services Editor, The Australian Dictionary of Biography (from 1971 to 2001)