Does international terrorism affect attitudes toward refugees? Does terrorism mobilize the public to pressure legislators to restrict refugee policy? Are these effects long- or short-lived? To answer these questions, this article presents results from a large-scale natural experiment to investigate the effects of the 2015 Islamic State terrorist attacks in Paris on attitudes toward Syrian refugees in a country that is a major recipient of refugees (Canada). The results demonstrate that the attacks increased (1) anxiety over refugee resettlement, (2) perceptions of refugees as a security and cultural threat, and (3) opposition to resettlement. Furthermore, the attacks increased mobilization among resettlement’s opponents. Using a large-scale survey (n=18,634
) fielded daily across a three-week period, however, we show that these effects were decidedly short-lived. The findings are highly relevant to our understanding of public reactions to major terrorist attacks and the responses of political entrepreneurs in their aftermath.