A new background report from START presents data that illustrate the dynamics of Islamic State-related terrorism over time and place, from 2002 to 2015. In particular, we investigate trends in the number of attacks and deaths caused by Islamic State-related terrorism over time, the geographic spread of Islamic State-related terrorism, and patterns of tactics, targets, and lethality of Islamic State-related terrorism.
Between 2002 and 2015, more than 4,900 terrorist attacks were carried out by groups or organizations affiliated with the organization now known as the Islamic State. These attacks caused more than 33,000 deaths and 41,000 injuries (including perpetrator casualties), and involved more than 11,000 individuals held hostage or kidnapped. Excluding incidents where the perpetrator group was not identified, these attacks represented 13 percent of all terrorist attacks worldwide, 26 percent of all deaths, 28 percent of all injuries, and 24 percent of all kidnap victims or hostages due to terrorism during the same time period.