Opposition to United States involvement in the Vietnam War An infamous photo of General Nguyễn Ngọc Loan shooting an alleged terrorist in handcuffs during the Tet Offensive also provoked public outcry. Another element of the American opposition to the war was the perception that U.S. intervention in Vietnam, which had been argued as acceptable because of the domino theory and the threat of communism, was not legally justifiable. Some Americans believed that the communist threat was used as a scapegoat to hide imperialistic intentions, and others argued that the American intervention in South Vietnam interfered with the self-determination of the country and felt that the war in Vietnam was
Canada in the Cold War in power believed that as long as the US president retained absolute control of the nuclear weapons, Canadian forces could be ordered to undertake nuclear missions for the US without Canadian consent. During the Cuban Missile Crisis, Canada was expected to fall in line with American foreign policy, in that Canada's military forces were expected to go on immediate war alert status. Diefenbaker however, refused to do so emphasizing the need for United Nations intervention. It would only be after a tense phone call between President John F. Kennedy and Diefenbaker that Canada's armed forces would begin preparations for "immediate