Robert A. Pape is professor of political science at the University of Chicago and director of the Chicago Project on Security and Terrorism. Michael Rowley is executive director of CPOST, where Sarah Morell is an undergraduate research associate. Follow CPOST on Twitter @CPOST_UChicago.

Before June 2014, most Americans were unfamiliar with the Islamic State. The vicious militant group—also known as ISIL—has dominated the international news since its takeover of Mosul and numerous Sunni-majority areas in Iraq and Syria this summer. ISIL’s notoriety reached new levels in August, however, with the beheadings of American journalists James Foley and Steven Sotloff and British aid worker David Haines. On Friday, ISIL beheaded another British aid worker, Alan Henning, and threatened to kill American aid worker Peter Kassig, a former U.S. Army Ranger.

These acts have stirred a visceral response and garnered extraordinary attention, with more Americans aware of Foley’s execution “than any other major news event in the past five years,” according to a recent NBC News/Wall Street Journal poll. September polls showed 60 percent of Americans now favor military action in Iraq and Syria, an increase from 36-39 percent in late June. The murders of these four individuals have profoundly disturbed the American people and government alike.


While these shocking actions have challenged average sensibilities and consciences, this violence has also led to assumptions about the motives for beheadings, and the group’s strategy as a whole, that are simply not true. The common misperception is that these beheadings are meant only to intimidate the West. On the contrary, beheadings are a deliberate strategy—one successfully employed in 2004 by Abu Musab al-Zarqawi, founder of al Qaeda in Iraq, ISIL’s predecessor organization, with the beheading of American Nick Berg—to improve recruitment efforts and build military strength to fight its enemies in Iraq and Syria.

To carry out this strategy, ISIL needs a serious injection of recruits to build upon its current fighting force of about 30,000 at most, which is significantly fewer fighters than each of its opponent forces: the Kurdish Peshmerga fighters, Iraqi and Syrian government forces and even potential Sunni tribal rivals. Simply put, ISIL is surrounded by enemies with greater fighting power, and needs to grow its military strength to create an Islamic—and Sunni—state inside Iraq and Syria.

So why the beheadings? In a word, publicity: They increase the group’s profile as the biggest challenger to the supposed greatest enemy of Islam. This allows ISIL to draw from a significantly larger pool of recruits, many with strong anti-American sentiment, which ISIL desperately needs to fight local battles as the group tries to carve out a de facto state. Yes, the beheadings are meant to challenge and intimidate the Western public, but that is only a secondary benefit for ISIL, whose focus remains on defeating enemies in immediate proximity.

Further evidence supports the assertion that ISIL is allocating resources to accomplish a regional, rather than a global, goal. ISIL has carried out well over 100 suicide attacks, all in Iraq, Syria and Lebanon. With as many as 30,000 fighters, including an estimated 2,000 Westerners, the group has plenty of capability to kill Western civilians. And yet, as of late August the United States remained “unaware of any specific, credible threats against the homeland.” Additionally, ISIL’s martyr videos (memorials to deceased members and a key recruitment tool) show footage of Western fighters burning their passports before carrying out operations leading to their deaths in Iraq or Syria. ISIL seems never to have planned for these fighters to return to the West to carry out acts of violence, instead utilizing them on the Iraqi and Syrian front lines. Indeed, the FBI is more concerned about an unrelated tiny cell of core al Qaeda members (the “Khorasan Group”) carrying out attacks against the West than it is about ISIL.

Strategic Beheadings of History The Islamic State may have shocked the world with its recent beheadings of two American journalists, two British aide workers and an unknown number of Syrian soldiers, but the terrorist group is by no means the first to employ public decapitations for political purposes. St. John the Baptist According to Christian tradition, Herod II beheaded Christian preacher John the Baptist at the request of Herod’s daughter, Salome, after John publicly denounced Herod’s marriage to Salome’s mother Herodias. (Herodias was not only Herod’s niece but had also previously been married to Herod’s brother.) Herod was more than happy to execute the influential religious leader. After the beheading, Salome delivered John’s head on a platter to her mother, a scene depicted here in a painting by Caravaggio. Greifensee soldiers In May 1444, after the Old Swiss Confederacy, the precursor of Switzerland, successfully captured the rebellious city of Greifensee, the confederacy’s troops beheaded 62 of the 64 remaining enemy troops to send a message to future adversaries. Here, a depiction via a 16th century Swiss illustrated chronicle. London Bridge Well into the 17th century, decapitated traitors and wrongdoers’ heads were displayed on stakes at the Southwark end of London Bridge to warn future plotters and criminals. London actually employed a “Keeper of the Heads” whose job was to monitor the bloody propaganda, which were frequently feasted upon by local birds. (Two of William Shakespeare’s distant relatives, John Somerville and Edward Arden, are assumed to have been on display around the time Shakespeare arrived in the city.) Here, a drawing by Claes Van Visscher. Marie Antoinette In 1793, four years after the beginning of the French Revolution, French Queen Marie Antoinette was convicted of treason. On Oct. 16, 1793, her hair was removed and Antoinette was carted around the city of Paris before finally reaching Place de la Révolution, where she was beheaded publicly by guillotine. Marie Antoinette was just one of scores of nobles beheaded in the revolution. Just months after she was guillotined, revolutionary leader Maximilien de Robespierre famously wrote, “If virtue be the spring of a popular government in times of peace, the spring of that government during a revolution is virtue combined with terror.” Imperial Japan Japanese samurai would decapitate not only adversaries but also cowardly soldiers that fled battle. Another brutal punishment, nokogiribiki, practiced until the late 19th century, consisted of burying a victim neck-deep and slowly sawing off his head with bamboo. One samurai who attempted to assassinate a feudal lord, was killed this way. Here, a depiction of the beheadings of Chinese soldiers during the First Sino-Japanese war.

With this in mind, the United States should be careful not to overreact. President Obama has employed the right strategy, which leans on airstrikes and mobilizing non-American local fighters to confront the ISIL threat. A major wave of airstrikes or other heavy uses of force are likely to accidentally kill innocent civilians, however, and feed the very anti-American sentiment that ISIL is seeking to cultivate and exploit. If the United States and its regional allies can strike carefully chosen targets from the air, while empowering local Sunni groups to oppose ISIL on the ground, then this strategy will likely drive a wedge between the group and its center of gravity in the Sunni community. This is more or less the strategy the United States successfully employed in 2006 in Iraq’s Anbar province, effectively crippling al Qaeda in Iraq.

An American strategy that overreaches would be particularly devastating considering the strong signs that Muslims reject ISIL’s tactics. And this is not just the case in Western countries: Anti-ISIL sentiment has grown among Sunni tribes after months of mistreatment, and some have even begun to act militarily against the group, just as the United States hoped. Ironically, the publicity ISIL is gaining from beheadings may have also planted the seeds of its own destruction.

This strategy, however, has not been articulated in the West. Instead, we are told that ISIL is a religious terrorist group bent on attacking Western civilians as its highest priority. The group recruits foreign fighters from Western and other countries and trains those new members to kill civilians in apostate countries like the United States. Some refer to ISIL as “evil” “barbarians” willing to commit indiscriminate violence against innocent people, all while harboring a special and deep resentment for the West. The use of moral language like “good versus evil” feeds into an already-common misperception in the United States about religion and violence, with 42 percent of Americans in 2013 stating that they believe the Islamic religion “is more likely than others to encourage violence among its believers.”

Americans may be prone to thinking that ISIL, with its evil and barbaric ways, must operate under a different moral code. Members of an Islamic extremist group—the thinking goes—must be carrying out their radical interpretation of Islam. The dots practically connect themselves: ISIL’s interpretation of Islam must inform the group’s violent behavior, and these beheadings—an acceptable form of execution under Islamic sharia law—are a manifestation of that religious fervor.

There is only one problem with this thinking: Precious little evidence exists of religious motives guiding the strategic logic of ISIL’s violence.

For more than a decade, the Chicago Project on Security and Terrorism (CPOST) has surveyed all known suicide attacks throughout the world since 1982 – incidents in Afghanistan, India, Iraq, Israel, Lebanon, Pakistan, Russia, Somalia, Sri Lanka, Syria, Turkey, Uzbekistan and others. This research on suicide attacks, an important way to measure group motives and behavior, has led to a clear conclusion: The main motives and circumstances surrounding nearly all instances of suicide attacks are political in nature, even for religious militant groups like ISIL.

What, then, is ISIL’s political goal? A Sunni militant group, ISIL primarily seeks to establish de facto sovereignty for Sunnis in territories in Iraq and Syria. To achieve this, the group is trying to rout the Shia-led Iraqi and Syrian governments who claim sovereignty over Sunni territories, and end what they believe to be an illegitimate occupation of Sunni territory. So ISIL attacks Shia government-controlled targets, like police stations and military bases, and attempts to control resources like water and oil as it consolidates power for the creation of a state.