ISISPatterns of ISIS-related terrorism, 2002-2015

Published 12 August 2016

Between 2002 and 2015, more than 4,900 terrorist attacks were carried out by groups or organizations affiliated with ISIS. These attacks caused more than 33,000 deaths and 41,000 injuries. These attacks represented 13 percent of all terrorist attacks worldwide and, 26 percent of all deaths, and 28 percent of all injuries due to terrorism during the same time period.

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, the paper 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.

START notes that between 2002 and 2015, more than 4,900 terrorist attacks were carried out by groups or organizations affiliated with ISIS. These attacks caused more than 33,000deaths and 41,000 injuries (including perpetrator casualties), and involved more than 11,000 individuals held hostage or kidnapped. Excluding incidents in which 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.

The report’s highlights:

  • In the early years there may have been significant overlap with al-Qaeda, a former ally of ISIS which is now its rival.
  • Until April 2013, almost all attacks (95 percent) by ISIS predecessors were carried out in Iraq. After that date, ISIS leader announced an expansion of his group to include the Nusra Front in Syria — though Nusra later distanced itself from ISIS.
  • April 2013 marks the beginning of the expansion of attacks by ISIS — not only geographically, but also in the number of attacks and their violence. Between 2013 and 2015, START found that there were 32 instances in which more than 10 IS attacks were carried out in a single day. All of these attacks took place in Iraq.
  • There was a further expansion in mid-2014, with groups who had sworn allegiance to ISIS now carrying out attacks in their name. The biggest increase came in March 2015, when the Nigerian Boko Haram pledged its allegiance to ISIS. Boko Haram added a considerable number of attacks to ISIS’s tally — almost 400 attacks that killed more than 4,000 people (including more than 1,000 attackers). START notes that recent developments suggest that the Nigerian group’s relationship with ISIS’s core is complicated and perhaps strained.
  • The type of violence perpetrated by ISIS and its allies differs from other terrorist attacks. Attacks by ISIS tend to be deadlier — 74.7 percent of ISI attacks were lethal during the period, versus 51.4 percent of non-ISIS attacks; on average, 7.3 people died per ISIS attack versus 2.1 in other attacks. ISIS attacks were also more likely to use suicide tactics or take hostages, and ISIS coordinated attacks 38.5 percent of the time versus 13.3 percent of the time for non-ISIS attacks.
  • Lone-wolf attacks by individuals inspired by ISIS have captured the headlines, but have made less of an impact. The report found that between 2002 and 2015, they made up less than 1 percent of all attacks.

— Read more in Patterns of Islamic State-Related Terrorism, 2002-2015, Background Paper (START, August 2016)