How does IS claim responsibility for a terrorist attack?

Why does IS bother to claim responsibility?
According to recent research by terrorism experts Justin Conrad and Max Abrahms, only one in seven terror attacks is actually claimed by the terrorist group responsible.

Given that the act of violence itself is meant as a performance – a way to remind the apathetic or ignorant of a group’s grievances and the costs of ignoring them – that number is surprisingly high.

Conrad and Abrahms argue that groups like IS are composed of two kinds of agents. One is rational leaders with strategic, political objectives. The other is operational foot soldiers, some of whom are not rational. IS’ leaders claim responsibility only when they calculate a political benefit; they refuse to claim responsibility when an attack might hurt the group’s objectives. Conrad and Abrahms analyzed hundreds of cases and conclude that this method is true not just for IS, but for other terrorist groups too.

If this theory is correct, IS claimed responsibility for both the recent Manchester bombing and the London Bridge assaults because its leaders calculated that it would result in a net benefit – like cash from its sympathizers or overreaction from its targets.

Such thinking might explain why no one, including the Taliban, has yet to claim last week’s attack in Kabul, which is believed to have claimed at least 150 lives and wounded another 300 people. We can speculate that something about the victims caused the perpetrators to calculate that it would be too politically costly for them to claim responsibility.

When would IS choose not to claim credit? When an attack results in heavy noncombatant casualties. For example, when Osama Bin Laden – whose group al-Qaida is considered by some to be less radical than IS – was interviewed by Pakistani journalist Taysir Alluni, he was challenged on the legitimacy of killing faithful Muslims who were in New York’s World Trade Center when it was destroyed on 9/11. He responded that these could not have been noncombatants because “Islamic law says that Muslims should not stay long in the land of infidels.”

This exchange shows that the meaning of “noncombatant” is not universal. Even nominal IS supporters may disagree with the group about who is a legitimate “combatant.”

Aren’t we giving IS too much credit? Do they really think strategically?
One of the most important insights to emerge in social science research on ethnic, religious and terrorist violence since the early 1990s, including my own, has been the recognition that groups representing hyper-violent operators do tend to act rationally and strategically. That means their actions and interests can be judged, patterned and predicted.

Monica Duffy Toft is Professor of International Politics, Tufts University. This article is published courtesy of The Conversation (under Creative Commons-Attribution / No derivative).