Born in Montreal, he attended Sir George Williams University and graduated from there in 1965 with a BA (Hons.) in history and was awarded the Lieutenant-Governor's Silver Medal for the highest standing in history. He continued his studies at the University of Toronto, receiving an MA and Ph.D in history in 1967 and 1971, respectively. His doctoral thesis was entitled “Labour in Winnipeg: The Great War and the General Strike”. In 1970-71 he was a visiting assistant professor at the University of Calgary. After he received his PhD, he was appointed assistant professor. He is now a full professor at the University of Calgary and director of the university's Centre for Military and Strategic Studies. He is also the Director of Programs at the Canadian Defence and Foreign Affairs Institute, based in Calgary.
He has published academic and commercial books on a range of subjects, focusing primarily in modern Canadian politics, Canadian defence and foreign policy, and Canadian military history. He has written, co-authored, or edited more than thirty books. He also writes regular columns for Legion Magazine, the Calgary Herald, and the National Post, among other publications. He periodically does political and military commentary for CBC and CTV television. In 1991, he co-authored with Barry Cooper Deconfederation: Canada without Quebec, where he argued that Canada would benefit from Quebec separation.
He was elected as a Fellow of the Royal Society of Canada in 1988. He received the J. B. Tyrrell Historical Medal in 2002 and in 2003 he was made an Officer of the Order of Canada. He was a recipient of the Vimy Award, which recognizes a Canadian who has made a significant and outstanding contribution to the defence and security of the Canadian nation and the preservation of its democratic values. Between 2002 and 2010, he was the Honorary Lieutenant Colonel of 41 Combat Engineer Regiment of the Canadian Forces. In 2012, he was awarded the Queen Elizabeth II Royal Jubilee medal.
- The Secret Army. Toronto: Lester & Orpen Dennys, (1983)
- Battalion of Heroes: The Calgary Highlanders in World War Two (1994)
- Maple Leaf Against the Axis, Canada's Second World War, Toronto: Stoddart, 1995; Tokyo: Sairyusha, 2003 (Japanese translation)
- Significant Incident: Canada's Army, the Airborne, and the Murder in Somalia, Toronto: McClelland and Stewart, 1996.
- (with J.L. Granatstein & R. Bothwell) Petrified Campus: The Crisis in Canada's Universities, Toronto: Random House of Canada, 1997.
- (with Holger H. Herwig) Deadly Seas: The Story of the St.Croix, the U305 and the Battle of the Atlantic, Toronto: Random House of Canada, 1997.
- Blood on the Hills: The Canadian Army in the Korean War. Toronto: University of Toronto Press, 1999.
- The Patricias: The Proud History of a Fighting Regiment. Toronto: Stoddart, 2001.
- (with H. Herwig), The Destruction of the Bismarck, New York: Overlook Press, 2001; also Toronto: Stoddart, 2001; London: Hutchinson, 2002.
- (with H. Herwig), One Christmas in Washington: The Secret Meeting Between Roosevelt and Churchill that Changed the World, New York: Overlook Press, 2005. Also, London: Weidenfeld, and Toronto: McArthur & Co.
- The Fighting Canadians: Our Regimental History from New France to Afghanistan, (2008)
- The Patricias: A Century of Service", Goose Lane Editions, 2013.
- David Bercuson at The Centre for Military and Strategic Studies
- Concordia University Honorary Doctorate Citation, June 1998, Concordia University Records Management and Archives