Operational, organizational, doctrinal, and cultural differences hampered effective command and control of Canadian and American maritime air power defending shipping against U-boats off the east coast during the Second World War. The American desire to implement US unity of command over both nations’ maritime air forces clashed with the Canadian preference for simple cooperation. Canadian airmen resisted several American attempts to impose unity of command until the operational situation in the Battle of the Atlantic revealed inefficiencies in coordination which necessitated all maritime air power in the Northwest Atlantic be centralized under Canadian operational control in the spring of 1943.
Goette, Richard "The Command and Control of Canadian and American Maritime Air Power in the Northwest Atlantic, 1941-1943." Canadian Military History 26, 2 (2017)