The reason 9/11 has not been repeated is because other tactics have — so far — worked better, faster, and far more cheaply

By Emerson T. Brooking

On September 11, 2001, terrorists murdered 2,997 Americans in 102 minutes. The collapse of the Twin Towers in New York City became the first media spectacle of the new millennium, broadcast on repeat to tens of millions of American homes. The United States was plunged into a state of fearful anticipation. Experts warned of more imminent attacks; of biological or even nuclear terrorism.

Twenty years later, those catastrophic attacks have not arrived. Militant jihadists have murdered a total of 107 individuals in the United States in the two decades since 9/11, an average of roughly five people per year. Far-right extremists, who now represent the principal US terror threat, have murdered slightly more over the same period. Yet no successful attack has come close to matching the terrible destruction wrought on 9/11. Indeed, few serious thwarted plots have aspired to do so.

The reason for this is only tangentially connected to the United States’ inefficient and frequently counterproductive $6.4 trillion-dollar Global War on Terrorism. Instead, the reason is best explained by the rise of the modern internet. The social media revolution has altered the organization, incentives, and broader context in which terrorist groups operate. As the world in which terrorists operate has changed, the face of terrorism has changed as well.

“Terrorism is theater,” as Brian M. Jenkins observed in his seminal 1974 RAND Corporation monograph. The purpose of politically motivated bombings, shootings, or assassinations is not to maximize fatalities, but to command attention. Terrorists use this attention to increase the visibility of their cause, strengthen their organizations, and compel their adversaries to action. By this measure, the 9/11 attacks were horrifically successful. Osama bin Laden and al-Qaeda became fixtures in global media, and their destruction became the singular focus of the US national security apparatus. On the day that the Twin Towers fell, Gallup found that the number of Americans who feared being the victims of an imminent terrorist attack had more than doubled to 58 percent. The mass death and terrible symbolism of 9/11 made the threat seem omnipresent and inescapable.

Yet as US-targeted terror attacks declined precipitously, American fears of terrorism did not. In September 2014, following the murder of two US hostages by ISIS militants in highly choreographed videos, fully 47 percent of Americans expressed fear of an imminent terror attack, higher than at any point since 9/11. ISIS’s abrupt domination of the American political discourse showed how social media manipulation and careful editing could inflate small acts of barbarity into much larger ones. In 2001, broadcast and cable media had made the 9/11 attacks impossible to miss. Now Twitter and Facebook could be used to magnify each horror that ISIS inflicted — and at a much lower price.

This vastly different information environment has wrought changes for terrorist organization and tactics. The 9/11 attacks were the culmination of a perilously complex five-year process involving nineteen al-Qaeda operatives under deep cover and supported by an international network of sympathizers. On the other hand, most ISIS-adjacent terrorism targeting the West was remarkable for its simplicity and lack of central coordination. “Remote control” attacks saw ISIS militants essentially serve as spiritual mentors to terrorist aspirants as they planned shootings, bombings, or vehicular murders in their home countries. In “lone-wolf” attacks, ISIS rushed to attach its brand to sporadic acts of violence that had been “inspired” by the group. Only ISIS’s November 2015 Paris attack, which resulted in the deaths of 130 people and required months of preparation, significantly departed from this trend.

Just as the nature of the modern internet has imparted more value to simpler terrorist attacks, it also requires that attacks come faster and with more regularity. According to diaries recovered from his Abbottabad compound in 2011, bin Laden spent the final months of his life reckoning with his own obsolescence. The leader of al-Qaeda could not understand how, less than a decade after 9/11, he was already being relegated to history and losing his place within the global jihadist movement. Essentially, bin Laden and al-Qaeda were ill-equipped to target internet-age attention spans, which reward shorter and more frequent engagement. By contrast, ISIS rose to prominence through its (sometimes tenuous) association with dozens of mostly small attacks between 2014 and 2017. More recently, far-right extremist and white supremacist terrorism have gained prominence thanks to the steady stream of terrorist acts associated with their ideology.

Finally, social media has opened the door to new kinds of spectacular, attention-grabbing terrorism whose novelty is unrelated to raw ambition or death tolls. The 9/11 attacks were so destructive, in part, because they had to be impactful enough to inspire potential terrorist recruits for a generation. ISIS, on the other hand, was able to transform something as basic as prisoner executions into extraordinary viral spectacles by inventing increasingly bizarre methods of murder and releasing the videos in high definition, distributed via Twitter botnets. The white supremacist terrorist responsible for the 2019 Christchurch mosque massacre went even further, building an entire internet community around his shooting by attaching a camera to his rifle and uploading a link of the first-person livestream to 8chan.

This, then, is the nature of modern terrorism: as rudimentary and repeatable as possible; laser-focused on maximizing its resonance across the global information environment. The reason that the catastrophic terrorism of 9/11 has not been repeated is because other tactics have — so far — worked better, faster, and far more cheaply.

Of course, it is possible this dynamic will shift again. The January 6 insurrection at the US Capitol building has been compared to the spectacular terrorism of 9/11 and, indeed, bears many similarities in its symbolism and the trauma it inflicted, absent the presence of mass death. It is also possible that, with the restoration of the Taliban in Afghanistan, militant jihadist terrorists may again find the space to plot catastrophic attacks abroad.

Regardless of these outcomes, one thing is almost certain. In the words of John Mueller and Mark G. Stewart, fear of terrorism has become “permanent or at least perpetual” in the years since 9/11, largely unmoored from the scale or danger of particular threats. This deep-seated fear has persisted for two decades. It will likely persist for many years more.

Emerson T. Brooking is a Resident Senior Fellow with the Digital Forensic Research Lab.

Cite this case study:

Emerson T. Brooking, “Op-Ed: How the internet changed the dynamics of terrorism after 9/11,” Digital Forensic Research Lab (DFRLab), September 9, 2021, https://medium.com/dfrlab/op-ed-how-the-internet-changed-the-dynamics-of-terrorism-after-9-11-f35f63c3e88b.

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