The terrorist attacks on several American cities on 11 September 2001, by Muslim militants linked to al-Qaeda negatively affected the disposition of many Americans toward Islam. These seismic events have also engendered a surge of latent religion into the public square. All the major religious traditions in the United States gained more visibility in national politics, ranging from tacit endorsements for presidential candidates and fervent debates over morally divisive issues, to aggressive evangelical activities at home and abroad. This surge in religious momentum raised questions whether America was heading toward a postsecular society, given debates about America as a Christian nation and the religiously inflected moral debates in public.

Internationally, the United States–sponsored wars in Afghanistan and then Iraq, followed by worldwide security sweeps, negatively affected America’s once-credible global image. In the non-West, especially in large swaths of the Muslim world, but also in parts of Europe, America’s image as a superpower morphed into that of a resented imperial power. Not since the Vietnam War had domestic and international politics become so intensely intertwined, but with one crucial difference. If the scourge during Vietnam was the red peril of Communism, then in the minds of significant sections of the U.S. public the threat in the first decade of the new century stemmed from Islam generally, and militant Islam, in particular.