The study addressed the relationship between terror attacks and public opinion among potentially supportive communities. We investigated whether terror attacks by Palestinian groups predict and are predicted by Palestinian public opinion. We examined the relationship of public opinion to total terror attacks, suicide attacks, and attacks by different groups. Increases in attacks predicted subsequent increases in public support for violence. Suicide attacks did not have a unique effect on support for violence, but suicide attacks by Hamas predicted increased support. Furthermore, increased public support for violence predicted subsequent increases in attacks by Fatah, Hamas and Palestinian Islamic Jihad (PIJ), as well as suicide attacks by Fatah and Hamas, but not PIJ. The findings suggest that effects of terrorism extend beyond targeted opponents to potentially supportive communities and that terrorism-using groups relying on public support may regulate their militant activities according to public opinion.