After the mid-20th century , Canada and the United States became extremely close partners. Canada was a close allie of USA during the Cold War.
William Lyon Mackenzie King (Prime minister) rejected free trade with the United States.
August 1957, the Canadian/American governments said they were going to integrate their air forces under a split command called the North American Air Defense Command (NORAD). This time during The Cold War, both Canada and the US feared long-range Soviet attack.
