1. Introduction

This year marks the 25th anniversary of “9/11.” And yet it already seems much further in the past. On the one hand, it has been almost a generation—nearly 40% of the EU’s population had not yet been born or were under 10 years old in 2001; in the U.S., the figure is even closer to 45%. On the other hand, so much has happened since 2001 that a state of perpetual political breathlessness has set in. From this perspective, September 11, 2001, seems to belong to a different era—and to a completely different world. That is not wrong. And yet it is worth looking back, because there are clear connections between the attacks in New York and many of the calamities that concern us today.

World War I is often called the “original catastrophe of the 20th century” because it gave rise—directly or indirectly—to numerous political and social upheavals that had long-term consequences: from the Russian Revolution, through the rise of fascism and World War II, to the division of Europe and the Cold War. Similarly, one could argue that the attacks of September 11, 2001, can be regarded as the “original catastrophe of the 21st century.” Not because they are comparable, in terms of their immediate death toll, to World War I or the great catastrophes of the past century, but because they triggered a chain of political decisions, international crises, and social dynamics, the consequences of which shape the present and are partly responsible for today’s diagnosis of a “polycrisis.” This thesis is not meant to imply that all of today’s problems can be traced back solely to that one day. Historical processes are complex and rarely follow simple cause-and-effect chains. Nevertheless, it is reasonable to assume that the attacks set in motion developments that have had lasting consequences for the present.

To understand this, one must first realize that the attacks themselves were unprecedented, both in terms of the number of victims and, above all, in terms of their symbolic impact. One must go back as far as Guy Fawkes’ “Gunpowder Plot”—the failed attack on the British Parliament in 1605—to even imagine something comparable in Europe. Within a matter of hours, a small group of terrorists succeeded in dealing a deep blow—economically, militarily, and politically—to the United States of America, which, as the sole remaining superpower after the end of the Cold War, had reached the pinnacle of its global standing. And this happened literally before the eyes of the global public. In many parts of the world, after just a single day, the great confidence, the spirit of optimism, and the climate of hope that had characterized the 1990s were profoundly shaken. After the end of the Cold War, many had believed that humanity had reached the “end of history” (Fukuyama) and stood on the threshold of a world that would be characterized by international cooperation, economic interdependence, global prosperity, and peace. The undeniable upheavals of the 1990s—from the collapse of Somalia and the Yugoslav Wars, through the genocide in Rwanda, to the wars on Russia’s periphery—were interpreted by many as teething problems of this new era. With “9/11,” however, this notion—perhaps already naive even back then—came to a remarkably abrupt end. Admittedly, this is a Western perspective—both the 1990s and “9/11” appear quite differently from the vantage points of Venezuela (Hugo Chávez), Nigeria (the Abacha dictatorship), or China (a capitalist shift without liberalism). And yet, the consequences of the developments following “9/11” ultimately did indeed affect nearly the entire world—primarily due to the United States’ influence on global politics.

In what follows, I would like to trace eight lines of development that began with “9/11” and that explain some of the most problematic aspects of our current situation. I will then explore the question of how things might proceed if we assume that historical trends—no matter how problematic they may be—do not create inevitable path dependencies, but rather that the future remains open and malleable.

2. The Consequences of “9/11”

2.1. The End of the Dream of a World of Democracies

Just ten days after the attacks in New York, then-U.S. President George W. Bush declared the “War on Terror” before the U.S. Congress. This “War on Terror” was initially directed against the Taliban regime in Afghanistan, which had provided sanctuary to the terrorist organization Al-Qaeda (the mastermind behind “9/11”). But the nature of the Western intervention in Afghanistan changed after the rapid military collapse of the Taliban regime: It became what would later be known as a “state-building” intervention—a model that was applied not only in Afghanistan but also, for example, in Bosnia and Herzegovina, Kosovo, East Timor, Somalia, Sierra Leone—and Iraq. Despite the deployment of enormous resources, it has become very clear over time: The idea of exporting democracy and stability (among other things, as a buffer against international terrorism) through (military) interventions was a mistake. And an extremely costly mistake in every respect—the intervention in Afghanistan alone cost 180,000 lives and (for the U.S. alone) two trillion U.S. dollars. And yet power vacuums, new civil wars, and new forms of terrorism and extremist violence emerged—in Afghanistan, the Taliban even returned. Rarely has international failure been so symbolically epitomized as in the spectacular collapse of the international intervention in Afghanistan in 2021—a full twenty years after “9/11.” In a sense, this also marked the definitive end of the last remnants of the dream of the 1990s: the new global era of peace and democracy neither emerged organically nor could it be “manufactured” in any way. In hindsight, one might dismiss the belief in it as astonishingly naive; however, one could also argue that the end of this vision on the international stage heralded a new era of “geopolitical thinking,” in which (as is the case today) normative questions about democracy and human rights are no longer even raised. From this perspective, the naivety of “the end of history” was followed by the self-fulfilling prophecy of cynical global power politics.

2.2. The Erosion of International Norms I: The International Criminal Court

The erosion of international norms and institutions that concerns us today can also be clearly linked to “9/11.” The U.S. withdrawal from the Rome Statute of the International Criminal Court (ICC) is emblematic of this. The “era of hope” in the 1990s saw the emergence of the idea to first, to address war crimes through the international legal system, and second, to eventually move away from establishing ad hoc tribunals (such as those for the Yugoslav Wars, the genocide in Rwanda, and the war crimes in Sierra Leone) in favor of a permanent International Criminal Court. The U.S. initially viewed this very positively, given its role in the Nuremberg Tribunals after World War II, and U.S. diplomats played an important role in the negotiations in Rome. However, concerns grew that the U.S. itself might come under the court’s scrutiny given its global interventions. Consequently, as early as 1998, the U.S. voted against the Rome Statute, alongside Iraq, China, and Libya (!). Nevertheless, U.S. President Clinton signed the Statute in 2000, though he did not submit it to the Senate for ratification (knowing full well that it would fail). The U.S. position, however, remained at least ambivalent, and the U.S. stayed involved in the process. This changed after the start of the “War on Terror.” In a diplomatically highly unusual move in 2002 under George W. Bush, the U.S. formally withdrew its signature from the Rome Statute at the UN. And they went even further. That same year, Congress passed the “American Service-Members’ Protection Act (ASPA),” which authorized the president to use “all appropriate means” to free U.S. citizens or allies from ICC custody—a move that led critics to dub the law the “Hague Invasion Act.” Against this backdrop, the new U.S. sanctions against the ICC, enacted in 2025–26, appear far less as part of “Trumpism” and more as a logical continuation of political courses set in motion shortly after 9/11.

Ironically, the very nation that had seen itself as the central champion of a rules-based international order during and after the Cold War began not only to reject but also to undermine a significant new aspect of that order as soon as the possibility arose that its rules might also be applied to its own actions. And these actions themselves, in the context of the “War on Terror,” did indeed increasingly spiral out of control. The infamous “Guantánamo Bay Detention Camp”—deliberately established outside U.S. jurisdiction and thus effectively beyond the reach of the law—was set up in early 2002; that same year saw the beginning of the unspeakable debate over “enhanced interrogation techniques” (commonly known as “torture”), and after the start of the Iraq War, the U.S. set up veritable “torture prisons” in Iraq, such as the particularly notorious one known as “Abu Ghraib.” The images from there have since become an indelible part of the iconography of moral failure in international politics. But the real problem was far greater: the grand dream of the 1990s—the “legalization of international relations,” nonviolent, law-based conflict resolution, and the imposition of sanctions for violations of international law—began to show glaring cracks. Today, that dream seems to have come to a definitive end.

2.3. The Erosion of International Norms II: The 2003 Iraq War

The Iraq War, which began in 2003, also marked a very significant turning point in other respects. The overthrow of Saddam Hussein took place under circumstances and with justifications that were met with skepticism worldwide and that later proved to be entirely unfounded. There was neither the alleged—or at least implied—connection to “9/11,” nor did Saddam Hussein’s regime possess weapons of mass destruction—as was claimed at the time to justify the war. Millions of citizens—not only in the U.S. and the U.K., which led the war—felt betrayed by their governments, while hundreds of thousands (!) of soldiers and civilians died in Iraq. With the benefit of hindsight, it can be said that “9/11” created a window of opportunity for the U.S. administration to push through its neoconservative-inspired agenda of “regime change” and the export of democracy with regard to a strategically important state in the Middle East. This came at the cost of a massive loss of trust among both its own and the global public, as well as severe damage to the international legal system and multilateral institutions.

The postwar order of 1945 was based largely on the idea that the use of force between states should be legally constrained and integrated into international procedures. The United States, in particular, was long regarded—despite all the contradictions in its foreign policy—as the most important guarantor of this system. The Cold War had paralyzed some of the relevant institutions, but, first, not all of them, and second, especially after the end of the Cold War, there was hope that these institutions and systems would finally function as they had once been intended. The Iraq War marked a profound turning point in this regard. The intervention took place without a Security Council mandate and on grounds that even the U.S.’s NATO partners had publicly dismissed as flimsy in the run-up to the war. This not only shook the Alliance but also, more broadly, undermined confidence in the binding nature of international rules—at precisely the moment when one might have hoped they could achieve universal validity. The long-term consequences are often underestimated. International orders depend on the willingness of actors to feel bound by the respective rules. If this self-imposed commitment is conspicuously abandoned, a dangerous precedent is set. While a violation of a norm by one actor does not legally legitimize the violation of the same norm by others, it certainly does so politically and in terms of propaganda. And this had a particularly devastating effect, especially following the “Decade of Hope” after the Cold War. Russia, in particular, knew how to exploit this weakening of the West’s normative authority in the years that followed—whether in the war against Georgia in 2008, the annexation of Crimea in 2014, or the large-scale invasion of Ukraine in 2022.

Taken together, one must conclude that it was by no means Donald Trump who initiated the shift in the U.S.’s role with regard to international law and the international order, but rather that this was the direct consequence of the “War on Terror” launched in the wake of “9/11.” With this “war,” the U.S. began to disregard and weaken international institutions, actively hinder their further development, and act increasingly outside any institutional and legal constraints—and, unfortunately, one must say: with virtually no restraint. Even the war against Iran launched by the U.S. in February 2026 is, in its specific form (i.e., completely bypassing the UN, with maximum rhetorical escalation, and by accepting significant civilian “collateral damage”) would be hardly conceivable without this history of dramatic erosion of international norms. Nor would a German chancellor speaking of “doing the dirty work.” Such a rhetorical gaffe would have been unthinkable during the 2003 Iraq War, which the German federal government clearly opposed at the time.

It is often overlooked that there is yet another crucial difference between the 2003 Iraq War and the 2026 Iran War: In 2003, there was an international debate, and the United Nations served as a central forum for it. At the time, it was probably unimaginable that this entire mode of politics at the international level would one day become obsolete. One must bear in mind: Back then, the U.S. went to the trouble of seeking justifications for the war and defending them publicly on both the national and international stages. And their flimsy claims were a scandal for which, for example, then-U.S. Secretary of State Colin Powell later expressed public shame. When the then-French Secretary of State Dominique de Villepin spoke out against the Iraq War in a polished speech before the UN Security Council in 2003, one month before the war began, it was a political and media event of global significance that instantly propelled de Villepin to international prominence. Who would be able to deliver such a speech today, and who would be interested in it? When then-U.S. Secretary of Defense Donald Rumsfeld sought support for the war at the 2003 Munich Security Conference, then-German Foreign Minister Joschka Fischer called out to him excitedly, “Excuse me, I am not convinced!” That, too, almost became a catchphrase at the time. Who would still assume today that “being convinced” is a relevant category in international politics? Jürgen Habermas also had to witness this sad legacy of “9/11.”

2.4. The Normalization of Violence

Another, often underestimated consequence of the reaction to the attacks in New York concerns the creeping shift from the logic of the rule of law to military logic. In the decades preceding the attacks in New York, even the most serious international terrorist crimes were understood as criminal offenses to be addressed through the means of the rule of law. The response to the 1988 Lockerbie bombing, in which Pan Am Flight 103 was destroyed over Scotland, generally followed this logic despite all the difficulties of international cooperation: investigation, indictment, and criminal prosecution. Incredibly laborious, incredibly time-consuming, incredibly protracted—but consistently within the framework of the rule of law. The Lockerbie trial began twelve years after the attack and ended with the verdicts eight months before “9/11.”

Eight months after “9/11,” the approach to Lockerbie was already unimaginable. With the declaration of the “War on Terror,” terrorists were declared enemies in a war. This completely shifted the normative framework of state action. But that was not all. Not only was the fight against terrorism now a “war,” but it increasingly became a war without boundaries. Even the laws of war (“ius in bello”) were no longer automatically recognized, since terrorists were officially deemed (as of 2002) by the U.S. to be “unlawful combatants,” to whom, for example, the Geneva Conventions were not supposed to apply. Torture (as at Abu Ghraib prison), extraordinary detention regimes (as at Guantánamo Bay), targeted killings (as in Pakistan, Yemen, Somalia, Libya, Afghanistan, or Iraq), and international military operations of all kinds were gradually normalized. This is perhaps the most devastating legacy of Abu Ghraib, Guantánamo, and drone strikes.

What is particularly noteworthy is that this development was by no means limited to the administration of U.S. President George W. Bush, who was in office during 9/11 (and whom many Europeans at the time considered the worst U.S. president imaginable). Under his successor, the “beacon of hope” Barack Obama, this process—through the drone war—even reached an entirely new dimension in some respects. The question of whether such coercive measures were compatible with the principles of state sovereignty, due process, and international law largely took a back seat to considerations of effectiveness and security. The result was a profound shift in the security policy thinking of Western democracies—not only in the U.S. International terrorism came to be viewed less and less as a transnational criminal problem and increasingly as a permanent state of military emergency. This simultaneously reduced the scope of the rule of law’s constraints on state behavior and further undermined the authority of international law. Only this background makes it understandable how it became conceivable to destroy suspected drug boats on the high seas along with their occupants (and to publicly boast about it with videos) or to simply kidnap a Venezuelan president and his wife. The loss of restraint in the use of military force by no means began with Donald Trump. It began with the “War on Terror.” And it must unfortunately be said that the continuities of this process have been overlooked for far too long—whether out of sheer ignorance or political expediency (as in the case of the drone war waged by Nobel Peace Prize laureate Barack Obama).

It’s safe to say that Germany has gone far less far down this path than the U.S., especially when it comes to the uninhibited use of force. But the intervention in Afghanistan, unfortunately, also provides sad examples here, such as the bombing of two tanker trucks ordered by a German colonel near Kunduz in 2009, which the officer regarded as a threat and in which he accepted the deaths of (according to estimates) over 140 civilians. Even the Federal Prosecutor’s Office later dropped the case, arguing that the incident had to be assessed according to the rules of “an armed conflict” and that it could not be proven that the officer had deliberately targeted civilians. Regardless of how one assesses the case in legal detail; what is remarkable is the military logic that dominated here as well in dealing with (even merely potential) terrorism—a logic in which the principle of human dignity (Art. 1, 1 of the German Basic Law) seems to vanish into “collateral damage.” And with an eye to the present, another example is cause for concern: The question of what Ukraine is actually doing with, among other things, German drone technology is not even being asked publicly. On the internet, relevant Ukrainian units are advertising (!) with video clips in which drones hunt down even unarmed Russian soldiers in no man’s land and do not stop until their bodies are torn to pieces—a scene that other drones then film in detail. In 2011, we at least only had to watch on the evening news as Obama watched Osama bin Laden being shot by U.S. soldiers (without the slightest attempt at due process); the killing itself was spared from public view at the time. But the path toward public desensitization was laid out in the “War on Terror.” Unfortunately, critical voices regarding this monstrous brutalization were—and still are—hardly heard in Germany either—the connections are simply not being made.

2.5. The New “Security State”

The “War on Terror” also had massive consequences for Western democracies themselves. Since the era of left-wing terrorism by the RAF, political scientist Wolf-Dieter Narr has polemically referred to the Federal Republic of Germany (BRD) as a “security state” with regard to the state’s response. It was only after “9/11” that Narr’s diagnosis truly became relevant. As we have seen, following the attacks, the principles of the rule of law were virtually irrelevant for the United States (and several other countries) in the fight against terrorism abroad. But that’s not all. Everywhere, security laws were tightened, surveillance powers were expanded, and civil liberties were curtailed. Measures that were originally intended as a temporary response to an extraordinary threat often became permanent. The state was granted new powers to collect and analyze personal data. Entirely new institutions emerged. Few people realize that the now-notorious U.S. agency “ICE” (“Immigration and Customs Enforcement”) is not an invention of Donald Trump, but rather a division within the “Department of Homeland Security” that was established after 9/11. From the very beginning, it had little in common with the sedate “Immigration and Naturalization Service” of yesteryear.

One doesn’t even have to look to the U.S. to see these effects: As recently as 2001–2002, the federal government at the time, under (Green Party!) Interior Minister Otto Schily, “anti-terrorism packages” that significantly expanded the powers of the Federal Office for the Protection of the Constitution, the BND, and the MAD (jokingly referred to at the time as the “Otto Catalogs”). This was followed by the expansion of “preventive surveillance,” the erosion of the separation between police and intelligence services, the introduction of biometrics in identity registration, and finally the Aviation Security Act of 2005, which would have permitted the shooting down of fully occupied passenger aircraft in a 9/11-style situation and was only blocked by the Federal Constitutional Court in 2006. In Germany, too, a political climate had emerged in which security concerns were given priority even over human dignity. It is noteworthy that it took the Federal Constitutional Court to remind politicians of the principle of human dignity.

This reveals the full paradox of the effects of 9/11: The “war on terror” not only led to new military conflicts and an erosion of the international order: In their efforts to protect their citizens from terrorist violence, Western democracies have, domestically, relativized the legal and normative boundaries that had long been among their most important strengths. If you will: liberal democracy began to undermine its own principles out of fear of its enemies.

2.6. The “True Core” of the “Clash of Civilizations”

No less significant were the cultural and social repercussions of 9/11. After the attacks, the question of the relationship between “Islam” and “the West” became one of the defining issues—even though this dichotomy was flawed from the outset. It was by no means over with the attacks in New York. There was a whole series of Islamist attacks—including in Europe: in Madrid (2004), London (2005), Paris (2015), Brussels (2016), Nice (2016), Berlin (2016), Manchester (2017), and Vienna (2020). Consequently, mistrust, polarization, and identity conflicts arose in many countries. While Islamist groups propagated the impression of a fundamental opposition between Islam and Western modernity, some Western actors—especially among the ranks of the increasingly powerful right-wing populists—adopted the narrative with the roles reversed. The idea of a cultural or civilizational confrontation gained traction. Nuanced perspectives were supplanted by simplistic friend-or-foe frameworks. Accordingly, attacks on Muslims followed—the NSU murders in Germany (through 2007), the attacks in London (2017), Bearum (2019), Christchurch (2019), and Hanau (2020).

With both the refugee crisis (after 2015) and the escalation and massive brutalization of the Middle East conflict after October 7, 2023, the issue then took yet another turn. But even Donald Trump’s infamous “Muslim Travel Ban” of 2017 (which remained in effect until Joe Biden took office and was reinstated in 2025—largely unnoticed by the public) is a direct result of this very climate. It can be noted that 9/11 marks the beginning of a chain of events that seems to at least partially validate Huntington’s “Clash of Civilizations” (1993)—the major counter-narrative to Fukuyama’s “End of History” in the 1990s. Here, too, the “War on Terror” played an exacerbating role, as it was not conducted in a way that would have undermined the conflict narratives mentioned above. On the contrary. The images of torture from Abu Ghraib, for example, have become deeply ingrained in the collective memory of many Muslims worldwide and can still be politically exploited. The bitter irony lies in the fact that it was the dashed belief in the “end of history”—and the rash and brutal reactions to that disappointment—that lent the “Clash of Civilizations” a certain plausibility in the first place. It is, unfortunately, not implausible to assume that this was precisely in line with the intentions of terrorist organizations.

2.7. The Original Digital Conspiracy Theory

Many Western democracies today are marked by a deep sense of crisis. Polarization, conspiracy theories, distrust of institutions, and the increasing fragmentation of public debates characterize many political systems. These developments have numerous causes, such as Digitalization or rising economic inequality. But here, too, 9/11 marks a profound turning point. The attacks ushered in an era in which fear, security concerns, and identity conflicts increasingly dominated the political agenda. And it is almost forgotten that the wave of major conspiracy theories spread via the Internet began with “9/11.” Conspiracy theories existed long before September 11, 2001. But for the first time—in the age of the internet and the then-emerging “social media” platforms—a global counter-public sphere emerged that reinterpreted a single historical event almost in real time and disseminated alternative narratives to millions. From the so-called “9/11 Truth” movements, a new pattern of political distrust emerged: governments, intelligence agencies, the media, and scientific experts were no longer merely criticized but increasingly viewed as part of a hidden power cartel. The decisive innovation lay less in the specific content of the claims than in the establishment of a way of thinking that later resurfaced in discussions of topics such as vaccinations, migration, climate change, election fraud, and the COVID-19 pandemic. The attack shook not only confidence in the security of Western societies but, for many people, also confidence in the ability of state institutions to credibly convey the truth about complex events. And the web of lies surrounding the Iraq War (see above) further fueled this perception. The fact that this mistrust gave rise to a counterculture that remains influential to this day is one of the less-noticed but most far-reaching long-term consequences of “9/11.”

2.8. The Refugee Crisis and the Rise of Right-Wing Populism

Among the particularly virulent developments following 9/11 is, not least, the destabilization of entire regions of the Middle East. Admittedly, the causes of the conflicts there cannot by any means be attributed solely to “9/11” or the “War on Terror.” Historical, social, and political factors played an equally important role in the “Arab Spring” (and its bloody failure in many places). Nevertheless, the events following 2001 constituted a significant part of the chain of developments that ultimately led to civil wars, state collapse, and massive refugee flows. In particular, the Syrian Civil War and the emergence of the so-called “Islamic State” (which, for its part, would have been inconceivable without the 2003 Iraq War) triggered migration flows that posed enormous challenges for Europe in the 2010s. The 2015 refugee crisis became a decisive catalyst for political polarization within the European Union. Issues of migration, border security, integration, and cultural identity took center stage in political debates. Populist and nationalist parties gained support. In many countries, the impression arose that established political elites had lost control over key developments. Trust in traditional parties and institutions declined. The effects were particularly noticeable in societies that were already marked by economic and social tensions. In Germany, for example, debates over migration and identity coincided with existing political discontent, particularly in parts of eastern Germany. The AfD was able to capitalize on issues that would likely have resonated far less without the migration crisis. Of course, there is no single cause for its electoral successes. The causes range from the experiences of reunification to the negative consequences of economic transformation processes to a general loss of trust in established parties. Nevertheless, it seems plausible to view the migration debate as a decisive mobilizing factor. And this debate, in turn, is linked to the political consequences of the developments that began after 9/11, including those in Iraq.

3. The Way Forward—25 Years After the Original Catastrophe?

The goal of Islamist terrorist organizations (both before and after “9/11”) was never to defeat Western states militarily. It is highly plausible to assume that their goal was rather to to sow insecurity, destabilize Western societies, weaken trust in liberal institutions, and deepen both the divide between the West and the Islamic world and the divides between Muslim minorities and their respective majority societies. Looking at the developments of the past twenty-five years, one must unfortunately come to the bitter realization that this strategy has been at least partially successful. The “9/11” attacks shattered the optimistic expectation of a peaceful post-Cold War order and ushered in an era of wars, interventions, refugee flows, and geopolitical power struggles, while the rules-based international order eroded. At the same time, the trust of many citizens in their own institutions was severely shaken, social cohesion was strained, and the internet emerged as a medium that acted as a catalyst for these processes. The destabilization of liberal democracies thus took place both internally—through polarization, mistrust, and populism—and externally—through the erosion of the international norms upon which their credibility rested. The legacy of 9/11 is therefore not only the destruction of the Twin Towers but this long chain of profound political and social upheavals, which continues to this day.

Yet historical developments are not natural phenomena. Precisely when one understands 9/11 as the primordial catastrophe of the 21st century, what follows is not fatalism, but responsibility. The history of the past quarter-century does indeed show how a single act of violence can trigger chain reactions. But it also shows that, ultimately, it was political decisions that determined what consequences this shock would have. The attacks were the trigger. The subsequent course of action was the result of political decisions. These decisions were often anything but wise. But they can be corrected.

The first step is to recognize these connections in the first place. All too often, the crises of the present are viewed in isolation or even reduced to the actions of individual, particularly high-profile politicians: here the erosion of international law, there the refugee crisis, elsewhere the rise of populist parties—and, time and again, Donald Trump. In fact, however, many of these developments are interconnected and the result of long-term processes. Anyone who understands the history of the past twenty-five years as a coherent narrative recognizes how closely foreign policy decisions, the international order, and domestic political stability are intertwined. Understanding these interconnections guards against the illusion that complex problems can be solved with simple answers or even by replacing individual politicians—no matter how visible or powerful they may be. Democracies, in particular, need this kind of historical self-reflection. They must neither make the mistake of repressing their own failures nor succumb to self-destructive blame games. Anyone who wants to understand why liberal democracies are under pressure today must therefore also be willing to openly acknowledge the misguided decisions of past decades—not to shift blame, but to learn from them.

From this understanding arises the second step: a conscious counter-movement against the developments that have gained momentum since 2001. If the consequence of 9/11 was an erosion of international rules, then these rules must be renewed and defended. International law does not regain its authority by merely invoking it, but rather by democracies being willing to credibly recommit themselves to its principles and to publicly criticize violations of them. (And there is clearly room for improvement in Germany as well!) If the terrorists hoped to drive open societies into fear and mistrust, then the answer lies in strengthening trust, freedom, and democratic resilience. If the past decades have been marked by polarization, then spaces must be created in which political opponents are once again perceived as fellow citizens and not as enemies. If migration and cultural diversity have become sources of social unease, then the task is not one of repression or demonization, but of pursuing policies that combine humanity, order, and integration. And if populists are capitalizing on a loss of trust in institutions, then these institutions must become more transparent, more effective, and more responsive to citizens.

In other words: Each of the problematic developments that have resulted from the chain of events following 9/11 also contains a clue as to how to overcome them. Perhaps this is where the most important lesson lies. The history of the 21st century does not have to follow permanently the course charted by the attacks of September 11. Historical causalities are not acts of fate. They create conditions, but they do not deprive societies of the freedom to correct their course. The true task of democratic politics, therefore, is to break free from the logic of path dependence: not to respond to fear with more fear, to power politics with power politics, or to polarization with even more polarization. Perhaps the most hopeful implication of this insight is therefore this: If ill-considered reactions to the dramatic events of a single day were able to change the world for the worse in the long term, then wise political decisions, democratic self-correction, and international cooperation can also change it back for the better. The history following 9/11 does not have to be the final word. It is a warning, not a verdict. Societies themselves still have the final say.

We.