During the 2009 H1N1 pandemic, the World Health Organization (WHO), acting under the authority of the International Health Regulations (IHR), recommended against the imposition of trade or travel restrictions because, according to WHO, these barriers would not prevent disease spread. Why did 47 states impose barriers anyway? This article argues that states use barriers as political cover to prevent a loss of domestic political support. This logic suggests that governments anticipating high domestic political benefits for imposing barriers during an outbreak will be likely to do so. Logistic regression and duration analysis of an original dataset coding state behavior during H1N1 provide support for this argument: democracies with weak health infrastructure—those that stand to gain the most from imposing barriers during an outbreak because they are particularly vulnerable to a negative public reaction—are more likely than others to impose barriers and to do so quickly.