The recent high-profile targeted killings of ISIS leader Abu Bakr al-Baghdadi and Iranian Quds Force General Qasem Soleimani have garnered a significant amount of press. What is rarely discussed publicly, however, is what scholarship has to say about the effectiveness of this counter-terrorism practice.
Especially worth noting are two research papers published by Jennifer Carson, Ph.D., of the University of Central Missouri, which suggest the practice has little effect on reducing terrorist violence.
Writing in Criminology and Public Policy (2017), Carson employed a robust quantitative methodological approach to assess how the deaths of ten high profile Al-Qaeda leaders between 2002-2013 impact rates of future terrorist violence.
The results of her study indicate that only three of those deaths reduced the risk of subsequent terrorist attacks within the global jihadist movement. In contrast, multiple other deaths of terrorist leaders were associated with increases in both the frequency and risk of future terrorist attacks.
The three instances were: the drone killing of senior Al-Qaeda operative Qaed Salim Sinan al-Harethi (2002), the assassination of Al-Qaeda leader Osama bin Laden (2011); and the 2012 drone killing of Al Qaeda’s purported number- two operative in Pakistan, Abu Yahyas al-Libi.
Accordingly, Carson concludes, “Although small effects consistent with a deterrence perspective were discovered, these become inconsequential when their backlash counterparts are taken into account.”
Note that a “backlash effect” refers to when the killing precipitates a “call to arms,” whereby public outrage over the killing at the hands of the U.S. provides the impetus for retaliatory violence.
For instance, after the death of al-Baghdadi in late October 2019, ISIS issued a formalized statement calling for revenge against the U.S., while similar echoes were made across social media by ISIS supporters throughout the world.
Carson’s follow-on study, in Crime and Delinquency (2018), explored similar outcomes across 31 targeted killings occurring between 2006-2014 in Pakistan, Somalia and Yemen.
The results of this study indicate that in eight instances of the deaths of high-value terrorist leaders, there was found to be a reduced risk of subsequent terrorist attacks in each of the three countries.
Importantly, these terrorist leaders were designated as “military” type leaders, in that they likely exerted some type of operational control over day-to-day operations within the group. It was assessed that the loss of these types of leaders—as opposed to political or mere figureheads of a group—may degrade the ability of the group to plan terrorist operations effectively.
Nevertheless, despite these positive findings, the overall picture from this analysis suggested that these targeted killings are not associated with the number of casualties from subsequent terrorist attacks, nor are they associated with the likelihood of subsequent high-casualty and suicide terrorist operations.
In fact, in several contexts, a backlash effect was observed, indicating that the risk of additional casualties from terrorist attacks actually increased.
Prior quantitative research on the recent use of targeted killings by the U.S. remains limited, and findings are decidedly mixed. For example, a prior 2014 study assessed the impact that the deaths of four Al-Qaeda leaders had on terrorist violence.
This study analyzed over 300 terrorist attacks in terms of their frequency, severity, type and success in the two months following the targeted killings of senior Al-Qaeda leaders. In the end, there was no evidence of retaliation (backlash effect); nor were there any significant changes in the type, target or frequency of attacks. In one regression model, there was evidence indicating that the number of fatalities decreased following the targeted killings.
A separate 2015 study examined the impact that targeted killings had on terrorist violence in Afghanistan and Pakistan between 2008-2011 and in Israel-West Bank-Gaza Strip areas between 2000-2004 and found that in the aftermath of a targeted killing strike, terrorist groups become far less discriminate in their target selection.
In other words, they tended to shift from attacking military targets to civilian targets. According to the authors, the primary explanation for this is that terrorist leaders tend to be more disciplined than their subordinates who have less knowledge of strategy. Put another way, while targeted killings were associated with changes to terrorist decision-making, the end result was simply more wanton violence directed towards civilians.
While the above studies do not offer definitive proof about the efficacy of high-profile targeted killings, they certainly do cast doubt on claims of these strikes constituting “major” or “decisive” blows against terrorist groups.
As others have argued in the past, the threat of targeted killings can be tactically beneficial by keeping terrorist leaders perpetually on the run, aid in the disruption of imminent terrorist plots, and under certain conditions may decrease the amount of terrorist violence over the short term. The benefits, however, seem to end here.
Possible adverse effects include significantly enhancing terrorist propaganda, turning terrorist leaders into martyrs, forcing groups to metastasize across larger areas, angering local populations, and losing face internationally—all of which may contribute to an escalation of violence.
Let us not forget that these secondary costs—which are less immediately obvious—also play important roles in determining how successful our counter-terrorism strategy will ultimately be.
Joseph Dule is a Research & Teaching Fellow at the University of New Haven, where he is completing his doctoral dissertation in Criminal Justice. Previously, he worked as an All-Source Intelligence Analyst in the U.S. Air Force, where he worked on Counter-Terrorism issues while assigned to the 320th Special Tactics Squadron, located in Okinawa, Japan. He welcomes comments from readers.