The Canadian Army was not a powerful fighting force in 1939-40. There were only 5000 full-time soldiers and 50,000 reservists. The army had only 16 light tanks, 4 anti-aircraft guns and two anti-tank guns. The officers and regular soldiers were very well-trained, but their training focused on First World War trench warfare tactics. The Canadian Divisions did not become modern viable fighting forces until 1942-43.

In the First World War Canada was still a colony of Great Britain, so when Britain mobilized its force, Canada's mobilization automatically started. By 1939 Canada controlled its own international relations and made its own military decisions. On September 1st Canada's government and military leadership created the Canadian Active Service Force, consisting of two infantry divisions ( roughly 30,000 soldiers ) for overseas duty. Call ups and training began as quickly as possible and by December, 1939 the First Canadian Division sailed for Britain. The Second Division followed in August 1940.