We review the current literature on why democracies experience terrorist attacks. Noting that most of these studies were based on data that ended in 2004, we update the data and analyze regime type and terrorist attacks through 2012. We identify a key trend: 2009 appears to have been a watershed year, where terrorist attacks began to occur more often in failed states and countries under military occupation than in democratic ones. Most strikingly, we find that autocratic regimes have experienced a modest increase in terrorist attacks, whereas democracies have experienced a generalized decrease. We then review the literature on terrorism in autocratic regimes, which is mainly focused on explaining variation in terrorist attack patterns across autocratic regimes with different capacities for coercion and co-optation and different sensitivities to audience costs. We conclude by highlighting some of the research and policy implications on regime type and terrorism.