A nation challenged: the impact of foreign threat on America's tolerance for diversity.

Three experiments investigated how perceived foreign threats to the United States can influence Americans' endorsement of assimilation and multiculturalism as models for foreign and domestic intergroup relations. The initial study, conducted during the 6-month anniversary of the September 11, 2001, terrorist attacks (9/11), discovered that a diverse group of Americans preferred assimilation as a foreign policy and multiculturalism as a domestic policy. After reading that foreigners were supporting the dominant global status of the United States, however, Americans in Experiment 2 no longer expressed this preference for assimilation as a model for foreign intergroup relations. Experiment 3 discovered that Americans primed with 9/11 (i.e., a foreign threat) revealed higher levels of national identity than did those primed with the Columbine massacre (i.e., a domestic threat); moreover, level of national identity predicted support for multiculturalism as a domestic policy and assimilation as a foreign policy.