This is the second post in a series which examines Canada’s Cold War. In our first post, we provided a framework to situate Canada’s postwar interests within a North American security context. Canada’s foreign and domestic policy in this era was to a large degree predicated by its role in the Commonwealth, but the geo-strategic vulnerabilities of northern North America forced a reorientation of Canada’s national allegiances. The United States replaced Britain as Canada’s primary security partner, and the Cold War’s impact on Canada must be understood accordingly.