Racist depictions of Japanese and other Asian immigrants were common well before World War II. Since immigration from Japan began increasing in the 1880s, Japanese were described as an invading horde or “yellow peril,” a threat to white society. After the bombing of Pearl Harbor, the U.S. government mass-produced propaganda posters showing racist stereotypes of a subhuman Japanese enemy — fanged, slit-eyed, devious creatures. The Japanese enemy was often pictured in the form of ugly and frightening animals, such as rats, bats, and other vermin. The decision to incarcerate all individuals of Japanese ancestry living on the West Coast in 1942 was influenced by widespread assumptions that people of Japanese descent were perpetually foreign and untrustworthy by virtue of their race.
Source: "Jap Trap," World War II propaganda poster, United States Information Service, 1941–45. From Densho Digital Archive, http://www.densho.org/. Courtesy of the National Archives and Records Administration (Ctrl.#: NWDNS-44-PA-2156; Office of Government Reports. United States Information Service. Division of Public Inquiry. Bureau of Special Services, OWI), denshopd-i37–00498 (accessed October 14, 2009).