A new dimension of military power emerging 

During the 1920s and 30's, a new dimension in military power was emerging. The decade was a time of rapid development in the field of aviation and aircraft capabilities. It was a time of immense excitement. There was intense competition between companies and nations involved in the then adolescent aviation industry. New aircraft and engines were being released almost every month. The newspapers carried front-page stories of advances and world records being broken. 

Forward thinkers of the time predicted that the next war would involve a great deal of military action in the air, as well as the immense land and naval battles of the past. The Allies would need many recruits, trained in new skills to new standards for an expanding Air Force. 

Britain was increasing its defence budget and rapidly expanding the Royal Air Force (RAF). At the highest diplomatic levels, they were inquiring whether Canada would contribute airmen directly. 

The Prime Minister had to balance his desire not to automatically commit Canada entirely to a European war ahead of time, which led to his personal game of ambivalence. He decided to wait and see if a war broke out, and then allow members of the Canadian Parliament to vote on any declaration or course of action.

Canada was still a Dominion of the British Empire when Hitler's Germany invaded Europe. A Special Session of Parliament and the Senate approved a Bill to Declare War on Germany. King George VI approved Canada's declaration of war with Germany on September 10th, 1939. 

The Dominion of Canada had a population of only 12 million at the time, and the Government anticipated that only a limited participation in a European War would be needed. Canadians, however, respond to the call, and applicants flooded recruitment offices. Throughout the war, the Canadian Army enlisted 730,000 personnel, the Air Force 260,000, and the Navy 115,000. 

As Europe moved closer to war in the late 1930s, the Canadian Prime Minister Mackenzie King realized and acknowledged that this war would be one involving air power. Mackenzie King and his Government discussed with Great Britain the role Canada could play in providing air training, as Canada had done during the Great War 20 years before.

The British quickly realized they did not have enough space or facilities to train the quantity that the Royal Air Force projected it would need to be successful. They immediately looked to Canada to contribute both recruits and facilities. Their calls were based on the precedent of the First World War, where Canadians joined the Royal Flying Corps, the Royal Naval Air Service, and the Royal Air Force, and training took place in Canada, well away from the front. 

Canada's open spaces, its distance from the theatre of war, its proximity to industry, including fledgling British and local American aircraft manufacturing branch factories, and numerous clear weather days compared to those in Europe, made it ideal for flying training. 

The need for trained pilots and aircrew was deemed a very high priority among the Commonwealth Nations. With Canada's lead, the BCATP was directly sponsored by the United Kingdom, Australia, and New Zealand as major partners. The Plan became one of the primary routes for training new military pilots and aircrew. 

One of the early and primary objectives of Mackenzie King's Canadian Government was to keep BCTAP Graduates together in future Squadrons under Canadian Officers and Commanders. For the Government, this was a contentious issue. The British position at the time was that such a hierarchical structure during a time of war would be divisive and inefficient. The Canadians stated that this command structure would help prevent the abuse of resources, mitigate operational risks, and enhance overall morale. 

The longer-term and more astute objective of the Prime Minister was to forge a stronger and more independent Canadian Air Force and utilize the entire Canadian war effort, both on the home front and on the front line, as an opportunity and an exercise in nation-building. If Canadians were to make sacrifices, Mackenzie King believed a stronger Canada must emerge.  

As a direct initiative of the Prime Minister Mackenzie King, during the negotiations with the British Representative Lord Riverdale, as listed under Article XV of the Agreement, graduates from Dominion Air Forces were to be assigned newly formed Operational Squadrons organized under their own Air Forces to work alongside the RAF, of if graduates were transferred to the RAF, a clear and specific national designations were to added to uniforrms. King saw this as an exercise in nation-building and a counter to the British assumption that they would directly absorb and assimilate recruits from the Dominions into the Royal Air Force (RAF). 

The final negotiations of the details establishing the BCATP between the four Dominion Governments (Canada, Great Britain, Australia, and New Zealand) took place in Ottawa during the latter part of 1939. The Air Training Agreement was signed on December 17, 1939, and remained in effect until March 1943, at which time it was to be reviewed

Canadians register to join the Air Force as train as Air Crews

 As the war began, numerous young Canadians, patriotic and eager for excitement, did not wait for Canadian recruitment to begin. Many travelled independently by ship across the Atlantic to England and enrolled directly in the RAF. At the time, this process was easy because citizens holding passports from Commonwealth countries could travel to Great Britain without any issues.  To mitigate this and direct Canadians to the Dominion's own Forces, the Canadian Government immediately started advertising via local newspapers, radio, and by placing posters on public notice boards. Recruitment offices opened across the country as quickly as possible, and qualified recruits were screened and assigned to waiting lists. 

The proposed ambitious target of the BCATP was to have at least 50,000 fully trained aircrew graduates each year. This was a projected commitment of at least 22,000 recruits from Great Britain, 13,000 from Canada, 11,000 from Australia, and 3,300 from New Zealand, the partner countries, to be trained annually as needed.