The Global Terrorism Index report analyzes trends in terrorism over the past 14 years. In 2013, deaths from terrorism significantly increased to over 17,000, with four terrorist groups (ISIL, Boko Haram, Taliban, al-Qa'ida) claiming 66% of deaths. Religious extremism based on interpretations of Wahhabi Islam motivates many groups, though political and separatist movements also use terrorism. Countries with high terrorism experience social divisions, state violence, and other forms of violence more than economic factors like poverty. The report identifies 13 countries at risk of substantial future increases in terrorism. Past successes against terrorism have involved policing or political processes more than military engagement alone.