How Should the World Respond to Terrorism?

Terrorism is an old phenomenon. To figure out how to end it, it’s worth sorting through what's changed, which precedents can inform future responses, and what past failures can teach for the way forward.

March alone saw a string of major terrorist attacks around the world—including in Ivory Coast, Belgium, Pakistan, Iraq, and Turkey—that together killed more than 100 people. The drumbeat of attacks seems horrifyingly constant, and underscores the fact that nearly 15 years since the United States launched its so-called global war on terror, victory is nowhere in sight.
So what would it take? Why haven’t the many counterterrorism policies tried in various countries around the world, ranging from major wars to tightened surveillance to Twitter counterpropaganda to outright repression, seemed to have made the problem less severe? Is it true, as Foreign Policy suggested recently, that when it comes to fighting terrorism, the international community is out of ideas?  Or, with ISIS steadily losing territory in Iraq and Syria even as it lashes out at the West, is the current campaign to some degree working?

Terrorism is an old phenomenon, and it’s one various countries around the world have absorbed and dealt with in various ways. In considering how to approach the current problem of terrorism around the world, it’s worth asking what’s really new about it, which precedents can inform future responses, and what past failures can teach for the way forward.


Historically speaking, terrorism is rare, and mass-casualty terrorist attacks rarer still. In terms of the sheer number of individual attacks committed in, for example, the United States and Europe, terrorism has actually declined significantly from its 1970s peak. (At the time, left-wing and right-wing terrorist groups were active throughout Europe; the United States had a particular problem with Puerto Rican nationalists.)

The U.S. has been especially safe from terrorism since September 11; the highest-casualty terrorist attack in the country since then occurred in San Bernardino in 2015, and yielded a death toll of 14 people. Overall the death toll from terrorism in the United States from 2004 to 2014, the most recent decade for which data was available, was 56, far below the toll of the 1990s, when 218 people died in terrorist attacks in the United States, 168 of them killed in the Oklahoma City bombing of 1995.
Still, the number of terrorist incidents worldwide, and the number of fatalities they cause, has jumped alarmingly in recent years, driven largely by events in just five countries—Iraq, Nigeria, Afghanistan, Pakistan, and Syria. As the State Department reported based on figures through 2014, “The number of terrorist attacks in 2014 increased 35 percent and total fatalities increased 81 percent compared to 2013,” partly due to the increasing lethality of some individual attacks. “In 2014, there were 20 attacks that killed more than 100 people, compared to two such attacks in 2013.”

On the other hand, no one really agrees on the definition of “terrorism”—there’s a reasonable degree of consensus that terrorism consists of politically motivated attacks by non-state actors, but it’s not clear where “terrorism” ends and acts of “insurgency” or “civil war” begin. As John Mueller and Mark Stewart pointed out recently: “Virtually any violence per­petrated by rebels in civil wars is now being called terrorism. ... Before 9/11, terrorism was, by definition, a limited phenomenon. ... If terroristic violence became really sustained and extensive in an area ... the activity was generally no longer called terrorism, but rather war or insurgency.” They concluded: “The post-9/11 conflation of insurgency with terrorism makes it seem that the world is awash in terrorism, something that stokes unjustified alarm outside war zones, where terrorism remains a quite limited hazard.”
Even with this expansive definition, less than 7 percent of violent deaths worldwide are the result of terrorism; as Micah Zenko pointed out in Foreign Policy last year, “Citizens of several Central American and Caribbean countries are still more likely to be the victim of homicide than Iraqis or Syrians are from terrorism.”