History has made us friends. Economics has made us partners. And necessity has made us allies. Those whom nature hath so joined together, let no man put asunder" (U.S. President John F. Kennedy).The cold war further strengthened the friendship between the two nations.
Sharing the longest border, the two nations although face modern difficulties such as immigration, environmental concerns, trade disputes and many other issues, the two countries have had significant interoperability within the defense sphere and are today the world's largest trading partners.
The United States and Canada expanded their formal military links at the operational level in the post world war period. The PJBD dealt with the political aspects of the defense relationships. A new body, the Military Cooperation Committee (MCC), was instituted to manage joint military planning between the American and the Canadian forces. Careful of surprise attacks after Pearl Harbor and concerned about the power of an increasingly hostile Soviet Union, American and Canadian defense officials used the bi-national planning structure of the MCC to set up the first joint continental defense initiative in 1946 called the Basic Security Plan (BSP). The Canadian Department of External Affairs (DEA) objected to the fact that it was denied access to the BSP working group by reason of its purported secrecy. The BSP was approved by both the United States and Canada in spite of these reservations. The PJBD and the MCC established a precedent of formal relations between Canada and the United States, providing for the coordinated defense of the continent. In 1949, Canada, the United States and their European allies formed the North Atlantic Treaty Organization (NATO). Canada and the United States were accorded their own Canada-US Regional Planning Group (CUSRPG) to look over the defense of North America within the larger NATO structure.
American planners were eager to get on with this new undertaking. But the Canadian government of Louis St. Laurent was hesitant. At issue for the Prime Minister and his Minister of Defense, Brook Claxton, were the implied costs and sovereignty infringements of a continental air defense expansion. The St. Laurent Liberals had experienced first-hand the American presence in Canada during the Second World War. Any suggestion by the United States of grander defense mechanisms invoked images of American soldiers on Canadian soil - and a corresponding loss of sovereignty. The Canadian military was seen to take a very different perspective. The Chiefs of Staff argued that the American concerns and recommendations were legitimate and Canada's involvement was absolutely indispensable. After the detonation of a massive thermonuclear device by the Soviet Union in 1953, the Canadian military officials implored Claxton and St. Laurent to reconsider their cautious approach.
Ultimately, Claxton recognized that Washington's steadfastness left Ottawa with hardly any option. The geography of North America and the nature of Canada-US relations were such that Canadian involvement in an improved continental air d