"Howard Clark became involved in nonviolent action as a student. As co‑editor of Peace News from 1971‑76, he was closely connected with several nonviolent initiatves ranging from the British Withdrawal from Northern Ireland Campaign to the Community Levy for Alternative Projects. Unemployed for the next five years, he had the time for a variety of activities mainly revolving around nonviolence training, safe energy campaigning and anti‑sexist work in schools. In 1981 he moved to Bradford to research first at the School of Peace Studies and then with the Alternative Defence Commission, being active in the local nuclear disarmament group. From 1985 to 1997 as coordinator of War Resisters’ International in London, Howard was in touch with a variety of projects and emerging nonviolent movements in many places, forming especially close links in Poland, South Africa and former‑Yugoslavia. He left WRI to become a Research Fellow for the Albert Einstein Institution studying the nonviolent struggle in Kosovo. He was a co-founder of the Balkan Peace Team, sending volunteers to Croatia, Serbia and Kosovo/a. " 
In 2009 he published the book People Power: Unarmed Resistance and Global Solidarity (Pluto Press) which included chapters from the following authors: Danijela Nenadic, Nenad Belcevic, Ivan Franovic, Yeshua Moser-Puangsuwan, Janet Cherry, Mauricio Garcia Duran, Anand Mazgaonkar, Brian Martin, Luis Enrique Eguren, Louise Winstanley, Christine Schweitzer, Rita Webb, Veronique Dudouet, Ann Wright, Angie Zelter, Kathy Kelly, Milan Raid, Cynthia Cockburn, Andreas Speck, Chesterfield Samba, Andrew Rigby, Stellan Vinthagen, Jorgen Johansen, George Lakey.
- 2000-present: Research fellow, Centre for Peace and Reconciliation Studies, University of Coventry.
- Currently project officer: Unarmed Resistance – the Transnational Factor (preparing international seminar in July 2006 and book)
- 1997-2000: Reseach Fellow, Albert Einstein Institution, Cambridge, Mass.
- 1982 - 1985: Researcher, Alternative Defence Commission, Univ of Bradford
Professional positions 1985-1997: Coordinator, War Resisters' International, London - "cooperating with groups engaged in nonviolent action in repressive conditions, such as (in chronological order) Wolnosc i Pokoj (Poland), End Conscription Campaign (South Africa), Peace Movement Working Group (Slovenia), Moscow Trust Group (USSR), Independent Peace Association and John Lennon Club (Czechoslovakia), Alba-Kor (Hungary), Federation for a Democratic China (European section), Palestinian Centre for the Study of Nonviolence, Institute for Peace and Culture of Nonviolence (Slovenia), Anti-War Campaign (Zagreb), Centre for Anti-War Action and Women in Black (Belgrade), Centre for Peace (Novi Sad), Council for the Defence of Human Rights and Freedoms (Kosovo), Izmir War Resisters' Association (Turkey)."
Selected roles in nonviolence and conflict transformation training:
- 2004: Caritas Internationalis, Co-facilitator for Peace and Reconciliation program, Caritas-Asia, Phnom Penh, Cambodia
- 2000–2001: Catholic Relief Services, Co-designer, Consultant and Co-facilitator on Peacebuilding training course in Kosovo
- 1995-2000: trainer for candidate volunteers for Balkan Peace Team
Selected voluntary roles
- from July 2006: chairperson, War Resisters' International
- People Power and Protest since 1945: a bibliography of nonviolent action – with April Carter and Michael Randle, London: Housmans, 2006
- Campaigning Power and Civil Courage: Bringing 'People Power' Back into Conflict Transformation, London: Committee for Conflict Transformation Support, 2005
- Balkan Peace Team Final Evaluation (with Christine Schweitzer), Minden: Balkan Peace Team/Bund für Soziale Verteidigung, 2002
- Kosovo Work in Progress: Closing the Cycle of Violence, Coventry: Centre for the Study of Forgiveness and Reconciliation, 2002
- “Nonviolent Struggle in Kosovo”, pp 196-203, in Michael Randle (ed), Challenge to Nonviolence, Bradford: University of Bradford Department of Peace Studies, Issues in Peace Research, 2002
- Demilitarising minds and societies, London: Committee for Conflict Transformation Support, 2001
- Civil Resistance in Kosovo, London: Pluto Press, 2000 (also published in German by verlag Weber-Zucht and the Institut für Friedensarbeit und Konfliktaustragung);
- “La resistencia no violenta en Kosovo: 1990-98” pp 59-104 in Informe Sobre el Conflicto y la Guerra de Kosovo, Madrid: ediciones del oriente y del mediterráneo, 1999
- Kosovo: Preparing for After the War, London: Committee for Conflict Transformation Support, 1999 (also published in German by the Institut für Friedensarbeit und Konfliktaustragung)
- Civil Society Approaches to Peace in Kosovo, Uppsala: Life and Peace Institute, paper for Swedish Ministry of Foreign Affairs' intergovernmental consultation - January 1999
- “More power than we know” in Gathering Visions, Gathering Strength, London/Leeds: Peace News/GVGS pamphlet, 1998 (reprinted by WRI in Choosing Peace Together, 1998, and translated into French, German and Spanish)
- “Das Ende des gewaltfreien Widerstandes in Kosovo”, Berlin: Gewaltfreie Aktion, heft 117/118, 3 + 4 Quartal 1998
- When the Best Say No: war resistance in South Africa, London: War Resisters' International pamphlet, 1989
- “Nonviolent resistance and social defence”, pp 49-69, in Gail Chester and Andrew Rigby (eds), Articles of Peace, Bridport: Prism, 1986
- Without the Bomb - for the Alternative Defence Commission, London: Granada, 1985
- Preparing for Nonviolent Direct Action – with Sheryl Crown, Angela McKee and Hugh MacPherson, Nottingham/London: Peace News/CND, 1983
- Atoms for War , London: CND, 1982
- Making Nonviolent Revolution, Nottingham: Peace News pamphlet, 1978 and 1981 (also published in Spanish)