Do Targeted Killings Weaken Terrorist Groups?

It has become a ritual: U.S. intelligence locates a terrorist leader, who is then killed either in an air strike or a special operations raid. The president takes a victory lap, saying, as President Joe Biden did on Monday after the death of al-Qaeda leader Ayman al-Zawahiri, “Now justice has been delivered, and this terrorist leader is no more.” Bipartisan lawmakers applaud while Islamist extremists mourn their “martyr.” Then a new terrorist leader arises and the process starts again.

Going After Kingpins

Do such killings have an impact? Do they make America safer and bring victory in the so-called war on terrorism any closer? For scholars of terrorism, those are very difficult questions to answer.

Some of the other “high-value targets” killed by the U.S. military or the CIA since 2001 are: al-Qaeda in Iraq leader Abu Musab al-Zarqawi (2006); al-Qaeda leader Osama bin Laden (2011); Anwar al-Awlaki, a leader of al-Qaeda in the Arabian Peninsula (2011); Afghan Taliban leader Mullah Akhtar Mansour (2016); Pakistani Taliban leader Mullah Fazlullah (2018); Islamic State leader Abu Bakr al-Baghdadi (2019) and his successor Abu Ibrahim al-Hashimi al-Qurayshi (2022); Iranian Quds Force commander Qasem Soleimani (2020); and al-Qaeda in the Arabian Peninsula leader Qasim al-Raymi (2020).

These strikes have disrupted terrorist operations and helped to prevent another 9/11-style attack, but they have hardly brought victory in the more-than-twenty-year war on terrorism any closer. The total number of Islamist militants, after all, is estimated to have grown as much as fourfold since the September 11, 2001, attacks notwithstanding all the losses suffered by the two leading Islamist extremist groups—al-Qaeda and the self-proclaimed Islamic State.

Patterns of Resiliency

Targeted strikes have done the least damage to the large organizations, which can easily replace top leaders. The Iranian Quds Force has not been noticeably slowed by the loss of Soleimani; it continues to carry out terrorist plots, back proxy militias, and to project Iranian influence across the Middle East. Likewise, the Afghan Taliban were not noticeably hindered by the loss of Mansour; five years after his death, they marched into Kabul as the United States ended its twenty-year campaign. Al-Qaeda in Iraq actually grew more powerful after the loss of Zarqawi in 2006; its power only began to recede after the U.S. troop surge in Iraq and the “Anbar Awakening” (when Sunni tribes turned on al-Qaeda) in 2007–08.

As for the Islamic State, the death of Baghdadi and Qurayshi was more a symptom than a cause of the organization’s decline. Both losses occurred after its self-declared caliphate in Iraq and Syria had been largely destroyed in combined arms operations involving tens of thousands of Iraqi troops and Syrian Kurd forces backed by U.S. firepower, intelligence, and other enablers.

In part, American commentators and officials are victims of their own imprecise terminology. They tend to lump together all Islamist militant organization as “terrorists” (a pejorative term), whereas groups such as the Islamic State and the Taliban should more accurately be described as guerrillas or even quasi-conventional armies. The Quds Force is sui generis as a branch of the Iranian government; it is a kind of Shiite extremist version of the CIA or the U.S. Special Operations Command. Just as armies and intelligence agencies can regularly replace lost leaders, so too can these extremist organizations.

A Weaker Al-Qaeda but Threats Remain

The loss of leaders hurts more for purely terrorist organizations, such as al-Qaeda, which are much smaller and less bureaucratic and, therefore, more reliant on charismatic leadership. Their followers are typically numbered in the hundreds, not the tens of thousands. The death of bin Laden was particularly important because he was such a famous symbol of jihadism. The United States was lucky that his successor was as uncharismatic and low-profile as Zawahiri. It is no coincidence that since Zawahiri took charge in 2011, al-Qaeda has faded as a global brand, while the Islamic State (led during its rapid expansion beginning in 2013 by the charismatic al-Baghdadi) has risen in importance.

Even though it can take a long time to kill terrorist kingpins (eleven years elapsed between the deaths of bin Laden and Zawahiri), the investment is worthwhile because the act of hunting them down reduces their operational effectiveness. Bin Laden and Zawahiri had to spend their time in hiding, communicating largely by courier. That slowed down al-Qaeda operations and made it easier to disrupt their plots. Al-Qaeda’s central organization is likely to splinter even more after Zawahiri’s death, since there is no well-known leader to take his place. Al-Qaeda’s reputed number three, former Egyptian colonel Saif al-Adel, is believed to reside in Iran and therefore is considered suspect by many of its adherents, all Sunni extremists.

But do not mistake victories over Islamist terrorist organizations with victory over militant Islam. The war on terrorism will not be won with targeted strikes on leadership. That will require political and economic reforms to address popular grievances and create more responsive governance in Muslim-majority countries. As Americans learned at high cost in Iraq and Afghanistan, to bring about those fundamental changes is beyond U.S. power.