The neighboring north Indian districts of Jaipur and Ajmer are identical in language, geography, and religious and caste demography. But when the famous Babri Mosque in Ayodhya was destroyed in 1992, Jaipur burned while Ajmer remained peaceful; when the state clashed over low-caste affirmative action quotas in 2008, Ajmer's residents rioted while Jaipur's citizens stayed calm. What explains these divergent patterns of ethnic conflict across multiethnic...