A minor quibble: though Craig Shirley asserts that the only way Americans could fight overseas before Pearl Harbour was with the Chinese air force, at least 16,000 Americans were serving in the Canadian Army, the Royal Canadian Navy, or the Royal Canadian Air Force:
Long before Pearl Harbor, a steady stream of Americans had started moving northward across the border to join the Canadian armed forces. By the beginning of 1941 some 1,200 Americans comprised about 10 percent of RCAF officer strength and 3 percent of the other ranks. A U.S. influx totaling about 10 percent of RCAF recruitment continued until, at the time of Pearl Harbor, over 6,000 U.S. citizens were serving in the RCAF, of whom 600 were instructors in the British Commonwealth Air Training Plan. By the same time nearly 10,000 Americans were serving in the Canadian Army. After Pearl Harbor a reverse movement resulted in the absorption of over 26,000 Canadians into the U.S. armed forces during World War II.
From Military Relations Between the U.S. & Canada by Stanley W. Dzuiban.
