The scale and audacity of the terrorist attacks on September 11, 2001, spurred sweeping changes in the way the United States, its partners, and adversaries used the machinery of state and technology to respond to threats. In this Council of Councils global perspectives, five experts reflect on the legacy of the attacks and offer insights into the biggest changes in counterterrorism, human rights, surveillance, international law of war, and border security.
The Full Circle of Counterterrorism
The 9/11 attacks were a defining event for global extremists and terrorists. Widely considered the most egregious act of international terrorism, it killed almost three thousand people (2,977 victims plus the nineteen al-Qaeda terrorists), injured an estimated twenty-five thousand, and inspired attacks in Bali, Djerba, London, Madrid, and elsewhere. The horror of 9/11 galvanized the world to come together to try to defeat terrorism. To address the common threat, military forces, law enforcement authorities, and intelligence services built common databases, exchanged personnel, conducted joint training and operations, shared intelligence, technology, expertise, and experience. The driving force behind the effort—the United States—now faces a new set of daunting threats.
The counterterrorism response to 9/11 evolved in four waves. First, the U.S.-led coalition in Afghanistan dismantled the Taliban and al-Qaeda infrastructure in 2001, captured 9/11 operational leader Khalid Sheikh Mohammed in 2003, and killed 9/11 mastermind Osama bin Laden in 2011. Dismantling the terrorist sanctuary in Afghanistan, where three dozen terror groups were training, prevented countless attacks worldwide. Although the CIA took ten years to find bin Laden, U.S. intelligence efforts targeted and eliminated terrorist leaders time after time.
Second, the United States invaded Iraq in March 2003—a fatal mistake. The hollowing out of the Iraqi military and the collapse of the administration led to a civil war, fostering an environment for the rise of al-Qaeda in Iraq. The U.S. drawdown created the self-proclaimed Islamic State, a movement that swept across Iraq and Syria. Although the Islamic State today is a shadow of what it was in 2015, its ideology and operational entities present a formidable threat to international security and stability.
Third, the United States established a dedicated Department of Homeland Security that brought its domestic intelligence and law enforcement entities under one umbrella. It also successfully prevented and preempted attacks against the U.S. homeland by fusing threat information and strengthening its counterterrorism capabilities to detect and disrupt threats.
Fourth, the United States spearheaded global counterterrorism programs by offering training and supporting governments that needed capabilities to fight their domestic and regional threat groups, networks, and cells. It built bridgeheads to penetrate and neutralize threats. The global war on terror was made sustainable. To complement the U.S. guiding search and destroy missions, U.S. partners built capabilities to challenge the quality of terrorist ideology.
China’s rise and the Russian annexation of Crimea distracted the United States, however, refocusing it on great power politics. Now that Afghanistan has fallen again to the Taliban, which hosted al-Qaeda in an uneasy alliance, the revitalization of al-Qaeda is inevitable. Between the return of Taliban and the continued peril posed by the Islamic State, the global threat of terrorism is as bad as or worse than it was twenty years ago. U.S. counterterrorism needs to be resilient. If chaos takes over in Afghanistan, a repeat of 9/11 is likely.
Now, though, United States is no longer the sole counterterrorism force in the world. China and Russia will need to protect their interests from terrorists at home and overseas. U.S. counterterrorism capabilities—despite the failure of Western forces to restore stability and security in Iraq and Afghanistan after two decades and a million deaths and injuries—are ten to twenty years ahead of any other country’s. Today, in terms of responsibility, a greater commitment by other countries, especially the great powers, is vital to stabilizing conflict zones and preventing and preempting terrorist attacks worldwide.
The War on Terror's Lasting Scars on Human Rights
In the two decades since 9/11, the international human rights system has been abused and weakened. The global war on terror has blurred the lines of war, terror, and human rights. This new kind of armed conflict—geographically and temporally unlimited—is fought between terrorists and counterterrorists, both of which violated human rights, as is now known definitively from a vast literature on the topic (see, for example, Joan Fitzpatrick, “Speaking Law to Power”; Aharon Barak, “Human Rights in Times of Terror”; Alan Fowler and Kasturi Sen, “Embedding the War on Terror”; William Miller, “Religion, Risk and Legal Culture”; and Victor Ramraj et al., “Global Anti-Terrorism Law and Policy”).
The United States not only co-opted allies in illegal actions such as using their territory for extraordinary rendition, but also further brutalized authoritarian regimes by pushing new counterterrorism legislation, handing over suspects caught in Afghanistan, Iraq, and Pakistan, and allowing arbitrary detentions and enforced disappearances. Such was the case of Egypt, Jordan, Morocco, and several Gulf states. In return for counterterrorism cooperation, the United States accepted violations of human rights in the form of prolonged states of emergency and hearing cases of ill-defined terrorism in special tribunals. For example, fewer than 2 percent of all cases in Jordan’s State Security Court from 2001 to 2006 were terrorism related. Thanks to Egypt’s state of emergency, some ten thousand people were held without fair trial. Egypt also learned from the U.S. Patriot Act how to structure its own counterterrorism bill, broadly defining terrorism as “infringing the public order, endangering the safety, interests, or security of society.” Brutalization and empowerment of these regimes led to greater public discontent over diminishing freedoms. That, among other causes, spurred the extraordinary series of events in 2011 known as the Arab Spring, causing some regimes to fall but leading in many to even greater violations of human rights today.
A consequence of the post 9/11 war on terror is that counterterrorism has become an accepted pretext for other, unrelated policies globally. China and Russia often use it to justify actions against opposition, activists, minorities, or interventions in third countries.
The brutalization effect also harmed democracies. The example the United States set and complicity of its European allies in illegal practices eroded the standing and credibility of the West. The perceived hypocrisy of democracies—prime guarantors and advocates of international law—undermined the integrity of that law altogether.
The furthest-reaching societal effects of the war on terror are yet to be felt. A sense of permanent insecurity, widespread surveillance, Islamophobia, and other kinds of xenophobia have already resulted in the proliferation of conspiracy theories and general decay of trust in politics and experts. The war on terror has come home to roost.
The New World of Surveillance
The 9/11 attacks fundamentally reshaped the U.S. intelligence community and those of many of its close allies. In the words of a former CIA station chief, the CIA underwent a massive transformation—from gathering to hunting. This new mission supported an emphasis on kinetic counterterrorism, enshrined in the 2002 U.S. National Security Strategy, with its determination to “disrupt and destroy terrorist organizations of global reach.”
The global war on terror required a shift in surveillance targets from traditional state threats and their militaries to much more amorphous terrorist networks. The nonstate actor threat required new tools and methods for surveillance. Led by the United States, the post-9/11 world of surveillance features an increasing reliance on a new tool of imagery intelligence—the drone—which rapidly became a dual-use weapon for both gathering and, in its armed form, hunting.
Drone use escalated during the Afghanistan conflict, as did attendant controversies about rules of engagement and civilian casualties. It spilled across borders, particularly into Pakistan, which harbored terrorist groups fighting in Afghanistan, and ultimately into other theaters, such as Iraq, Somalia, and Syria. Although the United States led in drone innovation, it quickly entered the intelligence and military arsenals of many other states. As commercial and technical accessibility grew and costs fell, it even into the hands of terrorist groups such as the self-proclaimed Islamic State.
A second critical development was the rise of domestic and global internet monitoring, and with it the advent of mass data collection and analytics. Ingestion of vast quantities of what is technically described as unselected information required new data storage, management, and analysis tools, including unprecedented computing power and the application of artificial intelligence to filter information. This new form of surveillance, representing as it did a historic turn away from targeted intelligence gathering, also needed a rationale, often depicted as finding needles in haystacks, but with a twist. Intelligence communities now argued that exploring the haystack was required to properly focus intelligence on its needle-like targets.
Mass data surveillance raised new global political tensions, which came to the fore with the revelations of the former National Security Agency contractor Edward Snowden, who revealed elements of the scale of the U.S. program, which operated in conjunction with the Five Eyes intelligence partners (Australia, Canada, New Zealand, and United Kingdom). The Snowden revelations also led to profound and enduring controversies over the legality of mass data surveillance and concerns over privacy protections and rights in democratic countries.
When state intelligence systems led, driven by a preoccupation with counterterrorism, the private sector followed. The corporate world may eventually use drones to bring parcels to our doorsteps, but what it really grasped was the potential for mass data surveillance and analytics to find, target, exploit, and keep consumer audiences, aided by the rise of social media platforms for expansive advertisement.
The growth of surveillance for intelligence and war fighting is a prime legacy of the 9/11 attacks. It has now found a wholly unexpected parallel existence in surveillance for commerce—the aptly named surveillance capitalism.
Meanwhile, threats lost sight of in the years of preoccupation with terrorism have reemerged, conjuring new forms of state surveillance. The experience of COVID-19 has introduced the world to the need for systemic health surveillance within and beyond national borders.
If there is an upside, it is that changes in the world of state and private-sector surveillance have also revitalized debates about global governance, democratic rights, accountability, and privacy.
The Legal Legacy
The U.S. and global responses to the 9/11 attacks have resulted in significant changes in interpretation to international law rules and state practice governing the use of force against terrorists. Some of the George W. Bush administration’s post-9/11 policies and legal interpretations were initially controversial, but many were later retained by the Barack Obama administration and adopted explicitly or tacitly by other governments.
Despite concerns expressed by human rights advocates, the Obama administration and many other governments accepted that governments may use military force against nonstate groups such as al-Qaeda and the self-proclaimed Islamic State and that the international laws of war, rather than simply domestic terrorism laws, may be the appropriate legal rules to apply. Many governments now also agree that threatened states may sometimes use military force against nonstate terrorist groups and terror suspects in unconsenting third countries if that country is “unwilling or unable” to mitigate the threat.
In its 2002 National Security Strategy, the Bush administration announced that the United States was prepared to act preemptively to counter threats from terrorists and rogue states even if the time and place of an attack remained uncertain. Although the preemption doctrine remains controversial, the Obama administration adopted a more flexible approach to the traditional international law requirement of an “imminent” threat to conduct hundreds of drone strikes against terrorists in Pakistan, Somalia, Yemen, and elsewhere. The UK government applied the same concept in the targeted killing of two British nationals in Syria in 2015.
One area in which international law rules have been hotly debated but remain unresolved two decades after the 9/11 attacks is the detention of terrorists captured by a state outside its territory. The Bush administration was criticized for placing hundreds of detained members of al-Qaeda and the Taliban in a “legal black hole” because it classified them neither as criminal suspects under U.S. law nor as prisoners of war under the Geneva Conventions. The Obama administration imposed stricter requirements for the humane treatment of detainees but continued to embrace the view that suspected terrorists could be detained under the laws of war until the end of the conflict. European governments similarly allowed Islamic State members captured in Syria to be detained as military combatants rather than prosecuted as criminals. Legal experts (including the International Committee for the Red Cross) now acknowledge gaps and “legal haziness” in the international law governing detention of terrorists, but unfortunately no consensus on what rules should apply has emerged.
In the meantime, thirty-nine terror suspects remain imprisoned in Guantanamo Bay, Cuba. Twelve, including Khalid Sheikh Mohammed, the mastermind of the 9/11 attacks, have been charged with war crimes and are being prosecuted by U.S. military commissions. These prosecutions, however, have been troubled from the start and could require another decade to conclude. Presidents Bush, Obama, and Biden have all expressed concern about Guantanamo, and President Obama ordered the facility closed, but the U.S. Congress has passed legislation that has made closure difficult. Guantanamo could continue to be the most obvious legal legacy of the 9/11 attacks for several more decades.
The Mirage of Perfect Border Control
Among the immediate reactions in Western countries to the attacks of 9/11 was a rise in anti-Muslim sentiments and a reframing of migration control as a way to counter the threat of further Islamist terrorist attacks. This led to a renewed emphasis on border security through the physical fortification of borders, a growing appetite for smart borders that rely on biometric data, and increased intergovernmental data sharing. Authorities initially asserted that terror attacks came from foreign actors who slipped across the border. The data, however, does not support this idea: the majority of jihadist attacks in the United States and the European Union (EU) have been carried out by citizens or legal residents of the country in question. Still, these efforts came with an illusion of the feasibility of a near-perfect control. The effects reverberate today.
The promise of greatly enhanced border security exposes politically moderate governments to constant right-wing populist pressure to demonstrate control. At the same time, it sets them up for failure given the unpredictable nature of crisis-driven mobility and the obligations of international human rights and refugee law. Developments in the European Union are a case in point: efforts to strengthen control over the EU’s external borders have led to a self-perpetuating dynamic of restricting access to asylum, prioritizing migrant return over other dimensions of migration, and increasing illegal pushbacks in which the EU border agency Frontex is complicit. At the same time, scholars point to a bifurcation of global mobility rights that entails a simultaneous easing of visa requirements between wealthy democratic states and greater restrictions for travel from poorer and nondemocratic states.
Although these developments were not triggered by any individual event, the 9/11 attacks did prompt a significant and lasting impulse to securitize migration and an emphasis on closure rather than on openness. Twenty years on, European governments’ reactions to the events currently unfolding in Afghanistan (that in and of themselves are a direct consequence of 9/11) bring the story full circle. Even days before the fall of the Afghan government, the European focus on migrant and refugee deportations to Afghanistan seemingly overrode concerns about the safety of local staff. By now, the collective failure to organize the timely evacuation of local staff is apparent, as are the pressing humanitarian needs within Afghanistan and neighboring countries. Nonetheless, a central strand of the debate in Europe invokes the fear of terrorists infiltrating the West and focuses on enlisting the governments of transit countries such as Turkey to ensure that Afghan refugees will not reach European territory in any significant number.
In this way, the mirage of—and subsequent fixation on—perfect border control continues to skew European governments’ perspectives on current crises. It also deepens their dependency on authoritarian governments savvy at exploiting the EU’s fear of uncontrolled immigration to their benefit.