Reza Aslan opens his book recounting an incident in which he awoke on a train in Morocco to the sound of an argument between a conductor and a married American couple. He stepped in as a translator. The conductor claimed to have caught the Americans acting inappropriately in public, while they claimed to just be sleeping. Both parties in Aslan’s telling had little patience or understanding for the other’s perspective. The conductor kept repeating he was a good Muslim and spat the word “Christian” out with disdain, while the couple—Christian evangelists to the Muslim world—tried to offer an insulting bribe and failed to realize how disturbing their evangelism was in Muslim eyes.

Aslan offers this encounter as evidence of the growing clash between American Christians, especially evangelicals, and many in the Muslim world after the terrorist attacks of September 11. He also gives examples of prominent Americans speaking of Islam with hatred or arguing that Muslims need to be converted to Christianity to create a better, more democratic, or more peaceful world. This rhetoric builds on the “clash of civilizations” thesis proposed by Harvard professor Samuel Huntington in 1996 that argues that Muslim culture is antithetical to Western culture and incompatible with modern liberal democracy.