3. Pearl Harbor led to national panic over Japanese intentions
Following the attack on Pearl Harbor and the early run of Japanese successes in the Pacific the population of the United States, particularly along the West Coast, began to fear a Japanese invasion of the continent. Politicians argued that the remnants of the US Pacific fleet should be brought to the United States to defend the mainland and the Panama Canal. While military authorities recognized the logistical difficulties which rendered a Japanese invasion an impossibility, their views were largely ignored, particularly by the anti-Roosevelt press which blamed American unpreparedness in the Pacific on the President and his long-standing efforts to support England against the Nazis in Europe. The press also exaggerated the presence of Japanese spies and saboteurs in the western states, where much of the defense industry was concentrated in 1942.
The press learned of a Japanese pilot who, after being involved in the Pearl Harbor attack (flying a fighter aircraft) crash landed his damaged airplane on the island of Niihau, the westernmost island of the Hawaiian chain. There he sought and found support from three Japanese-Hawaiian islanders. Eventually other Hawaiians learned of the Japanese pilot on the island and he was killed, as was one of those who aided him. Another collaborator committed suicide. An official US Navy report of the incident and its aftermath called the event proof that residents of Japanese descent would quickly change their allegiance to the Japanese if and when they arrived, and the anti-Roosevelt press continued the theme. By mid-February 1942 the government in Washington was being pressured to do something about the presence of Japanese on American soil.