World War II (1939–45)

There was no consultation when Britain declared war on 3 September 1939, though this time at least the Canadian prime minister, William Lyon Mackenzie King, and his government were united in their support. Canada’s own declaration of war was delayed because King had to assemble parliament to keep his promise that it would decide. When the Liberal-dominated House of Commons met in emergency session, starting on the 7th, the decision that had seemed so controversial a year before was accepted on the 9th almost unanimously. King repeated the pledge he had made in parliament in March not to introduce conscription for overseas service. His strategy had disadvantages, but it did help to bring Canada into the war without irreparable division.

The Canada led by King would play a significant role in the war. Convoy duty by the Royal Canadian Navy had begun immediately, in September 1939, and in December the 1st Canadian Division of the army went overseas. Isolated after the fall of France in June 1940, Britain would depend on the industrial and military might of North America for its survival. In the darkest days, Canada was a major source of troops and supplies. The United States would provide a lend-lease arrangement for materials in 1941 and then become an active ally, but Canada, in proportion to its size, made a larger contribution. Industrial production expanded rapidly, and the government’s generous financial arrangements made it possible for Britain to purchase Canadian food and munitions. The effort was remarkable by any standards.