AFTER FOUR YEARS OF CARNAGE Canada emerged from the Great War in 1918 bloodied but victorious, with a strengthened sense of national confidence and pride. The nation shared a feeling that it had come of age, its soldiers having proved themselves equal to any other combatants in their courage, ability, and self-sacrifice across the western front, at Vimy Ridge, and in the fields of Flanders. Canadian attitudes towards Great Britain changed significantly. Though English Canadians still considered theirs a British nation, they could no longer be content to be treated like colonial children by the mother country whose men they had fought alongside on the road to victory. The Canadian government began to insist on equality of political representation, sending its own delegation to the postwar negotiations at Versailles. Within a decade it would appoint Vincent Massey its first ambassador to Washington, and the British embassy no longer presumed to speak on behalf of Canadian interests in the United States.

The end of the war also brought about changed relations and attitudes towards the United States. Long-held prejudices against the presumed arrogance of Americans were reinforced by the self-congratulatory attitudes of their politicians and press, who boasted that American intervention had won the war. Canadians bitterly pointed out that the United States had joined the fighting three years after Canadians entered the war and that, relative to population, Canada had suffered ten times more casualties. Nevertheless, the United States and Canada had fought together as allies, and the United States emerged from the war rich and powerful, while Britain was exhausted and nearly broke.