The United States effectively countered enemy attempts to frame the Mexican War as a holy war against Catholicism. An actively engaged and hostile civilian population could have seriously jeopardized U.S. military operations during the invasion of Mexico. President Polk and General Scott planned and executed a strategy of conciliation toward Mexican civilians that sought to keep them on the sidelines of the contest. Negating a holy war narrative put forward by Mexican leaders was central to the U.S. strategy of conciliation. The United States accomplished this by incorporating Catholic priests into its army of invasion, cooperating with Catholic Church leaders, both in Mexico and in the United States, and by respecting Church property and symbols. Both U.S. political and military leaders accomplished this all during a time of strident anti-Catholicism in the United States. Although different in time and circumstance, the United States again finds itself fighting an adversary that seeks to put forward a narrative of holy war in reaction to perceived attacks on its faith. The U.S. experience in Mexico can be used to help shape potential approaches to countering such a narrative.