Kilsoo Haan, American Intelligence, and the Anticipated Japanese Invasion of California, 1931–1943

To what extent did U.S. intelligence believe that Imperial Japanese forces would invade the West Coast, an idea that many believe was responsible for the alleged atmosphere of wartime hysteria that led to mass confinement of West Coast Japanese Americans? Based on unused archival materials, this article shows that these agencies dismissed the idea of an impending Japanese invasion, shown by their negative reaction to Korean nationalist Kilsoo Haan’s “Yellow Peril” prediction of a Japanese invasion of California in 1943. It also demonstrates that assumptions about Yellow Peril ideas require more nuanced analysis, for they were not universally accepted or as widespread as often believed. The article concludes with observations on Kilsoo Haan, U.S. intelligence, and Japanese American internment.