when did canada and the us become allies
Canada–United States relations The Canadian military, like forces of other NATO countries, fought alongside the United States in most major conflicts since World War II, including the Korean War, the Gulf War, the Kosovo War, and most recently the war in Afghanistan. The main exceptions to this were the Canadian government's opposition to the Vietnam War and the Iraq War, which caused some brief diplomatic tensions. Despite these issues, military relations have remained close.
Canada in the Cold War To defend North America against a possible enemy attack, Canada and the United States began to work very closely together in the 1950s. The North American Aerospace Defense Command (NORAD) created a joint air-defense system. In northern Canada, the Distant Early Warning Line (Dew Line) was established to give warning of Soviet bombers heading over the north pole. Great debate broke out while John Diefenbaker was Prime Minister as to whether Canada should accept U.S. nuclear weapons on its territory. Diefenbaker had already agreed to buy the BOMARC missile system from the Americans, which would be not as effective without nuclear warheads, but balked at permitting the weapons into Canada.