This research demonstrates a common psychology of outgroup hostility driven by perceived intergroup threat among three groups and seven cultural contexts: non‐Muslim Westerners, Muslims in Western societies, and Muslims in the Middle East. In Study 1, symbolic, but not realistic and terroristic threats, predicted non‐Muslim Norwegians' intentions to join anti‐Islamic movements. In Study 2, symbolic and realistic, but not terroristic threat, predicted non‐Muslim Americans' willingness to persecute Muslims. In Studies 3 and 4, symbolic threat predicted support and behavioral intentions against the West among Swedish and Turkish Muslims. Finally, in Study 5, a comparison demonstrated that symbolic and realistic threats had the same effects on violent intentions among non‐Muslim and Muslim Danes, and Muslims in Afghanistan. Meta‐analysis showed that symbolic threat was most strongly associated with intergroup hostility. Across studies, participants with high religious group identification experienced higher levels of threat. Implications for intergroup research and prejudice reduction are discussed.