Mercenary eagles: American pilots serving in foreign air forces prior to the United States entry into the Second World War, 1936-1941

While American aviators have sold their services to foreign governments since the early years of the age of flight, the time from the outbreak of the Spanish Civil War in 1936 until the United States entry into the Second World War in late 1941 was the golden age of mercenary pilots. The involvement of Americans in foreign conflicts during this period represented a challenge to the stated neutrality policies of the United States. At the outset, Americans were pursued for violating the Neutrality Acts and other federal laws. The building international crisis of the late 1930s forced President Franklin D. Roosevelt and key members of his administration to reconsider their position. With the invasion of Poland in September 1939, the Roosevelt administration quietly relaxed its enforcement of statutes that prohibited Americans from enlisting in foreign air forces. As the war turned against the British Commonwealth, Roosevelt gave private assurances to the Prime Minister of Canada that endorsed the Royal Canadian Air Force establishing an official recruiting agency within the United States. The declining strength of the Nationalist Chinese government in its struggle against Imperial Japan in late 1940 prompted the administration to become a direct participant in the organization of an aviation foreign legion for China.; The changes in the administration policy toward Americans flying for foreign air forces was a precursor, not a reflection, the United States' shift from isolationism toward interventionism. From a policy of persecution of Americans involved in Spain in 1936–38 to official permission to recruit from the U.S. military by the Chinese in 1941, allowing American pilots to enlist in foreign air forces became a means of confidential assistance to embattled nations. While not a secret policy, the decision makers at the highest levels of the Roosevelt administration often did not reveal their intentions to their own bureaucracy or the general public. Particular care was taken during 1940 to avoid any impact upon Roosevelt's reelection campaign. Once a third term was achieved, the administration moved aggressively toward intervention in the Sino-Japanese Conflict with air power for the Kuomintang. The study of the activities of mercenary pilots and government policy during the period revealed a Roosevelt that was more willing to intervene in the world's hot spots, more interested in taking action in both Asia and Europe, and taking belligerent actions ahead of, rather than tagging behind, general public opinion.