Even prior to the outbreak of the Korean War, Ottawa was no stranger to the postwar environment on the Korean peninsula. Canada had been a member of the United Nations Temporary Committee on Korea (UNTCOK) since its creation in 1947, a commission formed with the goal of holding free elections in 1948 and reuniting the peninsula. North Korea’s refusal to allow UNTCOK to host free elections in northern regions of the peninsula dashed any hopes that UNTCOK or its successor, the United Nations Committee on Korea (UNCOK), would aid in reunifying the Republic of Korea with the People’s Democratic Republic. Despite their frustration with the inefficacy of UNCOK, the Canadians certainly had not anticipated the violence that would erupt in divided Korea.
North Korea’s invasion of South Korea in the early hours of 25 June 1950 brought about the first major armed conflict of the postwar era. Although Canada was not eager to become enmeshed in a conflict so far abroad, Prime Minister Louis St. Laurent made Canada’s commitment clear: “Any participation by Canada [...] would not be participation in war against any state. It would be our part in collective peace action under the control and authority of the United Nations for the purpose of restoring peace.” 
Beginning with the deployment of three Canadian destroyers from British Columbia’s coast to Korean waters on 5 July, the Canadians entered the Korean conflict with armed support, not just diplomatic backing. This briefing outlines the military and diplomatic calculations involved in Ottawa’s decision-making with respect to the Korean conflict, beginning with the invasion of South Korea in June 1950 through to the order for full withdrawal announced in late 1954.
Over these four years, major shifts reframed how Ottawa approached the conflict—when fighting first broke out, Canada was eager to get troops on the ground to support the United Nations effort. However, a lengthy stalemate and eventual armistice, along with misunderstandings about Canadian intentions and American disregard for Canada’s traditional chain-of-command, caused Canadian enthusiasm to wane considerably and Ottawa began pushing for a swift return home for all ground troops. These military interests were also balanced by diplomatic interests; though eager to bring their troops home, Canadian diplomats did not want to be seen as shirking their United Nations responsibilities and hoped Canadian participation in the ground war would give them greater leverage in any peace negotiations.
Throughout these documents, the Canadian government wrestled with serious concerns that would haunt them for decades to come. What would Canada’s place in the international order look like in the atomic age? How could Ottawa remain a good and reliable ally to Washington and London, whilst still maintaining an independent foreign policy? Would Canada’s military apparatus be able to make its own decisions, or would it merely form a complicit cog in international forces like the United Nations Forces or the Commonwealth Forces?
 Denis Stairs, The Diplomacy of Constraint: Canada, the Korean War, and the United States (Toronto: University of Toronto Press, 1974), 59.
Bercuson, David J. Blood on the Hills: The Canadian Army in the Korean War. Toronto: University of Toronto Press, 1999.
Granatstein, J. L. Canada’s Army: Waging War and Keeping the Peace, Second Edition. Toronto: University of Toronto Press, 2011.
Stairs, Denis. The Diplomacy of Constraint: Canada, the Korean War, and the United States. Toronto: University of Toronto Press, 1974.