Canada fought in the Vietnam War. The country's troop deployments to Vietnam were limited to a small number of national forces in 1973 to help enforce the Paris Peace Accords. Nevertheless, the war had considerable effects on Canada, while Canada and Canadians affected the war, in return.
During the First Indochina War between France and the Indo-Chinese nationalist and communist parties, Canada remained militarily uninvolved but provided modest diplomatic and economic support to the French. Canada was, however, part of the International Control Commission (along with Poland and India) that oversaw the 1954 Geneva Agreements that divided Vietnam, provided for French withdrawal and would have instituted elections for reunification by 1956. Behind the scenes, Canadian diplomats tried to discourage both France and the United States from escalating the conflict in a part of the world Canadians had decided was not strategically vital.
Canada laid out six prerequisites to joining a war effort or Asian alliance like SEATO:
These criteria effectively guaranteed Canada would not participate in the Vietnam War.
At the start of the Vietnam War, Canada was a member of the International Control Commission (ICC) overseeing the implementation of the Geneva Agreements, and thus attempted to maintain an air of neutrality. However, the Canadian negotiators were strongly on the side of the Americans. One representative (Blair Seaborn, younger brother of Robert Seaborn) was even involved in secretly exchanging messages between the U.S. and North Vietnam on behalf of the Americans, with the approval of the Canadian government. Canada also sent foreign aid to South Vietnam, which, while humanitarian, was directed by the Americans. Canada tried to mediate between the warring countries, aiming for a conclusion that could allow the U.S. to leave the conflict honorably, but also publicly (if mildly) criticized American war methods.
Meanwhile, Canadian industry exported military supplies and raw materials useful in their manufacture, including ammunition, napalm and Agent Orange, to the United States, as trade between the two countries carried on unhindered.