The relationship between Canada and the United States has been shaped most clearly by its asymmetrical nature and a movement toward increased interdependence. Except for the size of their national territories, the gap between the two countries is sweeping. Be it in the realm of population size, economic production, political capital or military power, the United States outnumbers Canada many times over. Facilitated by the spatial distribution of most of the Canadian population along a 100-mile wide line along the Canadian-American border, both countries have developed a more and more intertwined relationship, most prominently in the economic and cultural realm. This was intensified by the First and Second World War. During the early 1920s the United States surpassed the United Kingdom as Canada's largest foreign investor and became its major trading partner. The increasing permeability of the border, furthermore, allowed for American cultural products and lifestyles to enter Canadian society. Cultural penetration and a growing economic interdependence that raised fears of a de facto dependence thus solidified Canada's junior position in this unequal relationship at the onset of the Cold War (Doran, 94-96).
As a result of this imbalance, a peculiar sense of Canadian ambiguity with respect to its southern neighbor had developed, ranging between the recognition of shared interests and apprehensions about American influence. An awareness of such feelings can be found in both countries. Lester B. Pearson, Secretary of State for External Affairs from 1948-1957 and later Prime Minister noted in his memoir that until World War II Canadian self-determination was primarily conditioned by decisions made in London. "[I]t was now the United States that had that power," Pearson wrote, "a hard fact which brought us anxiety as well as assurance." Even as he acknowledged the necessity for close cooperation, Pearson expressed concern about the power imbalance, writing that "as a debutant on the world stage we were worried, not about rape, but seduction" (Pearson 31, 33). In fact, he writes, "we may have gone merely from the colonial frying pan into the continental fire" (Pearson, 114).
Yet, in contrast to some Canadian officials' views , such perceptions did not go unnoticed south of the border. Noting a "growing sense of nationalism," the New York Times wrote in 1956 that Canadians "complain that the United States tends to take them too much for granted and to treat their country as though it were a forty-ninth state." Not commenting on whether such feelings were legitimate, the article recognized that they were "responsible from time to time for magnifying minor irritations into major aggravations" (Daniell). By the same token, Dwight D. Eisenhower recollected that he "knew that, because of the comparative size of our two nations, our Canadian friends sometimes suspected us of arrogance." Addressing such feelings resulting from the asymmetrical relationship between both countries, he remarked in his memoir that it was his "government's intention to approach all our common problems in a spirit of friendly understanding" (Eisenhower, 241). As these statements show, Ottawa and Washington were aware of the political implications their unequal but intimate partnership entailed.
The American political scientist Charles F. Doran distinguishes among three major spheres that characterize Canada-U.S. relations: the political-strategic, the trade-commercial, and the psychological-cultural dimension. Whereas Canada was primarily interested in maintaining a beneficial economic relationship, the United States tended to emphasize the political-strategic dimension, as its trade volume with Canada has been comparatively low in relation to the overall American economy. Even though these two dimensions were important in their own right, Doran argues that the psychological-cultural realm formed the most important sphere of Canada-U.S. relations. Reflecting the power imbalance inherent in the relationship, he explains that "the United States may find Canadian complaints irritating; Canada frequently finds the American presence suffocating" (Doran, 41). Elaborating on this aspect, Doran writes that
Americans tend to ignore the potential impact that American television programming has on a large Canadian viewership; or the impact that textbooks published in the United States and exported to Canada can have on learning; or the effect U.S. advertising can have on Canadian purchasing habits; or the effect an American tourist infusion can have on Canadian provincial parks and natural areas
Canada's foreign policy, furthermore, played an important psychological and cultural role in shaping a Canadian national identity. Canada's participation in both world wars instilled a sense of national accomplishment and pride. Taking up this idea, Pearson noted that "Europe was not only the cultural homeland of most Canadians, it was the battlefield on which we first became nationally conscious and proud of our Canadian identity" (Pearson, 29).
The renowned Canadian historian Donald G. Creighton wrote that Prime Minister Mackenzie King was convinced that World War II "had made Canada a sovereign nation and that this achievement must be made manifest to the whole world by the removal of the remaining emblems of colonialism and the substitution of the symbols of independent nationhood" (Creighton, 128). The large influence of American culture, therefore, tended to produce adverse responses as it conflicted with Canadians' idea of national maturity. A 1965-report of the Canadian ambassador to the United States, A. D. P. Heeney, and the American ambassador to Canada, Livingston T. Merchant, underlined this assessment saying that "'the danger from the United States to English-speaking Canada is that of cultural absorption, while for French Canada it is cultural destruction'" (Merchant, 4).
The asymmetrical and increasingly interdependent relationship between Ottawa and Washington thus was characterized by an ambiguous perception in which shared interests coexisted alongside with Canadian concerns about an overwhelming American presence. With the establishment of intimate defense cooperation during World War II, which formed the foundation for Cold War defense relations, Canadian wariness was further fanned. Pearson accordingly commented on the state of Canada-U.S. relations in 1951, noting that "'the days of relatively easy and automatic relations between our two countries are over'" (Pearson, 114).