How do insurgents choose their tactics in civil wars? While most
theories of civil war violence marginalize the role of ideology, we
argue that the location, type, and lethality of insurgent violence are
all shaped by the underlying spatial distribution of civilians'
relative support for combatants. Unlike current ``hearts and minds''
theories, we contend that pro-government attitudes are associated with
increased, not reduced, violence, and that these attitudes predict
future attacks. A survey experiment in 204 Afghan villages is used to
establish a positive association between pro-International Security
Assistance Force attitudes and future Taliban attacks. We extend our
analysis to 14,606 non-surveyed villages, where our measure of
civilian attitudes improves out-of-sample prediction by 20--30\% over
standard forecasting models. The results are especially strong for
Taliban attacks with improvised explosive devices. These findings hold
even after adjusting for possible confounders, including past violence,
military bases, and aid. (Last Revised, January 2016)