Using a new conceptual framework, this study documents and analyses the underlying convictions of influential Canadians, explains why there were such varied degrees of support for NATO, and shows why different leaders either supported or rejected nuclear weapons and the stationing of the Canadian Forces in Europe. Examples taken from previously classified documents illustrate how the underlying convictions of leaders such as Prime Minister John Diefenbaker and Prime Minister Pierre Trudeau significantly shaped defence policy. Behind-the-scenes maneuvering and competing beliefs about nuclear weapons, deterrence strategy, and possible entrapment in a nuclear war led some to defend and others to criticize Canada's approach to both NATO and the bomb. Despite the technological ability and resources to develop its own nuclear weapons - or to acquire them from the United States - Canada ultimately chose not to become a nuclear power. Why did some Canadian leaders defend the nuclear option and urge the deployment of the Canadian Forces in Europe? Why did others condemn the country's nuclear commitments and call for an end to the arms race? Simpson shows that some leaders rejected prevailing American defence strategy and weapons systems to pursue alternative approaches to managing Canada's complex bilateral and multilateral defence relationships.