We study the spatial and temporal determinants of terrorism risk in Israel, using a geocoded database of Israeli terrorist attacks from 1949 to 2004. In selecting targets, terrorists seem to respond rationally to costs and benefits: they are more likely to hit targets more accessible from their own homebases and international borders, closer to symbolic centers of government administration, and in more heavily Jewish areas. We also examine the waiting time between attacks experienced by localities. Long periods without an attack signal lower risk for most localities, but higher risk for important areas such as regional or national capitals.