Over the past year, ISIS has stunned the world with its rapid territorial advance in Iraq, Syria, and now Libya as well as its horrifying violence against civilians. But what if ISIS is succeeding not because of its brutality, but in spite of it? A recent study by Page Fortna, a Columbia University political science professor, suggests that’s the case, arguing that, while extremely hard to defeat, terrorist groups like ISIS have a nearly impossible time achieving their political goals.
Fortna’s paper, published in the journal International Organization, looks at the use of terrorism by groups fighting in civil wars. This constitutes the vast majority of terrorist violence around the world, though it gets much less attention than spectacular attacks in cities at peace like Paris or New York. Most major terrorist organizations, including ISIS, the various branches of al-Qaida, and Boko Haram, are just part-time terrorists—they spend much of their time fighting in civil wars against militaries or other armed factions like traditional rebel groups. But not all rebel groups use terrorism, defined for the purposes of the paper as “a systematic campaign of indiscriminate violence against public civilian targets to influence a wider audience.” This provides a comparison to determine whether terrorism “works,” and the data suggests it does not.
Using an existing data set of 104 rebel groups involved in civil wars between 1989 and 2009, 24 of which employed high-casualty terrorism, Fortna found zero instances of terrorism-using groups defeating the governments they were fighting outright. Non-terrorist rebels, however, won about 20 percent of the time. This doesn’t mean that terrorist groups never win. Fortna concedes there may be examples of arguable terrorist “successes” outside this data set: the French withdrawal from Algeria, for instance. There are also instances of groups that use terrorism winning concessions through peace agreements. Nelson Mandela’s African National Congress, which carried out bombing attacks on civilian targets during the 1980s, achieved essentially all of its goals with the eventual end of apartheid. The Irish Republican Army received concessions from the British government in the 1998 Good Friday Agreement. But negotiated outcomes are far less common for terrorists than non-terrorists, and terrorists often get fewer concessions.
Besides, many terrorist groups have ultimate goals that preclude negotiated settlements: The Iraqi government, for instance, won’t ever be able to sign a peace deal with the Islamic State without renouncing its own existence.
Fortna found that the results held even after controlling for factors such as the relative strength of the rebel group or the extremity of its goals. She argues that the typically cited advantages of terrorism—it’s cheaper than conventional warfare, it signals fanatical commitment to a cause, it can provoke governments to politically damaging overreaction—are outweighed by its disadvantages: Terrorism can alienate potential supporters and justify harsh government crackdowns.
So why do groups use terrorism if it’s not effective? It may be for survival. Fortna writes that “wars in which rebels used terror were much more likely to be ongoing as of 2009 than were wars with nonterrorist rebels, suggesting that terrorism makes wars particularly difficult to terminate.” Because of the relative ease of terrorism compared with traditional warfare, groups that use it can stay active for longer. A recent example of this dynamic is al-Shabaab, which has continued to mount deadly attacks in Somalia and Kenya even as it’s lost nearly all the territory it once controlled.
ISIS appeared on the scene too late for the paper’s data set, but Fortna told me she suspects the group’s “use of terrorist activity is undermining their strength. Their recent military advances are coming despite their use of terrorist tactics, not because of them.”
Fortna is skeptical of the claim, which I explained here, that ISIS’s very public brutality helps it attract recruits, noting a lack of empirical data. But the two arguments aren’t necessarily contradictory: The group’s terrorism attracts the fighters it needs to keep itself in business even as it alienates the locals whose support, or at least cooperation, it will need to build its planned “state.” Terrorism, Fortna says, “is undermining their legitimacy in the territory they’re trying to conquer and mobilizing international opposition against them.”
Fortna hopes her research leads to a more realistic assessment of the threat posed by ISIS and other terrorist groups. “In the current post-9/11 climate, I think there’s a tendency to elevate the potency of terrorist groups because what they do is so headline-grabbing,” she told me. “Yes, they’re scary, but scariness does not lead to politically efficacy or military efficacy.”
Still, on a day when Boko Haram, a classic terrorist/rebel hybrid group, carried out another suicide bombing killing dozens in northeast Nigeria, it’s hard to feel comforted by Fortna’s paper. These groups may not win, but they’re going to be with us for a long time.