September 11 remains a day when we reflect on how terrorism has changed not only the way states respond to the phenomenon, but also how citizens react to government decisions, international affairs, and counterterrorism measures under the fear of victimization.

The attack perpetrated by Al Qaeda set the scene for a new way-at the time- to look at terrorism and address it. It allowed states to introduce an aspect of securitization in various levels of daily life, communication, and travel, and to forge the dogma of “war against terrorism,” not without challenges to human rights, civil liberties, and even territorial sovereignty. But the global scene today is quite different from what it was in 2001, with terrorism evolving and public attitudes changing.

In more than two decades, Al Qaeda has not disappeared, but Daesh has managed to steal the show. It succeeded in making people suspect it as the Islamist boogie man after every lone actor attack that bore Islamist traits. For example, a “Allahu Akbar” cry was often enough for people to assume that Daesh was behind a knife attack. Even if this was not the case, the organisation still benefited in terms of its terrorist reputation. Daesh even tried to establish territorial dominance, and after its defeat, it still left behind a legacy of further security risk: foreign fighters. Across the globe, terrorism has employed a wide range of violent tactics, from suicide bombings (which have become less prevalent over time), to vehicle ramming, knife assaults, hostage-taking, and the use of rape and sexual abuse. Long-standing terror groups have stopped their activity and given up arms altogether (e.g., ETA dissolved its military structure in 2018), while other new small groups (e.g., in Greece) seem to appear and disappear, while it is suspected that they re-emerge under different names. This last pattern points to a persistent pool of recruits ready to act under various terrorist group labels. The internet has become a vital tool for terrorists who use it for rhetoric, narrative, propaganda, communication, and recruitment.

Security experts have widely adopted and promoted the concept of “radicalization,” a term notably ambiguous, which refers to a path (that no expert has yet managed to accurately map) paved by a variety of grievances- societal and/or personal- in an attempt to explain why people commit acts of terrorism, join terrorist groups, or act independently under ideological or religious affiliations. Scholars were reminded that religion can be a powerful driving force behind human activity (a surprising realization after decades of secular theories, minimizing the importance of religion). They were also reminded that financial, institutional, and social problems can also pave the way for “radicalization” and terrorist violence. Thus, along with religious terrorism, interest re-emerged for more secular forms, like far-leftist, anti-authority, and far-right/nationalist terrorism. However, as experts began mapping the evolving threat of terrorism, a new reality surfaced: many actors are no longer fully committed to a single ideological base. Instead, they adopted a more fluid ideological position, choosing bits and parts from different belief systems to justify their violence (hence the new “salad bar”” ideology as it has been called).

In the wake of these changes, the Hamas attack on 7 October, as well as subsequent military operations by Israel, further complicated the security landscape and highlighted the subjective application of the term “terrorism” within public discourse. Polarization and support of the “right side” seems reason enough to ignore textbook, classic terrorism that results in civilian casualties, including the elderly and babies. The operational methodology of hostage-taking, used by Palestinian groups also during the 1970s, proved to be once again one of the most challenging situations for security officials (an actual dead-end). Israel’s response to the terrorist attack on October 7 that also injured its citizens psychologically and emotionally cannot be without limits. The right to self-defense does not give the reader a carte blanche; human rights conventions and the Geneva Conventions set specific limits. Public opinion can serve as a necessary and powerful watchdog, with global protests and advocacy pressing for humanitarian approaches, for war crimes to stop, for the application of international law. Criminalizing or obstructing the solidarity expressed to Palestinian civilians is unacceptable on many levels. However, it is concerning that the support for the rights of Palestinians is frequently voiced without a parallel condemnation of Hamas’s tactics or clear demands for the return of hostages to Israel. Expressions of support to the Palestinian side have taken the form of direct rejection of the right of the State of Israel to exist at all (and a crucial question is raised: if Palestinians deserve a state that ensures their security, safety, and prosperity, why should Israelis be denied the same?). Additionally, certain arguments place collective responsibility on all Israelis, and even Jews worldwide, for the decisions made by the Israeli government, even if thousands of Israelis march and protest those decisions. This reveals bias and antisemitism masked as support for Palestinians, not genuine interest in the rights of the Palestinian people.

The U.S. after 9/11 implemented “enhanced interrogation techniques”, which were forms of torture, and facilities such as Guantanamo Bay and Abu Ghraib became central to these practices. Moreover, the wars in Afghanistan and Iraq have contributed to further instability and grievances leading to radicalization. Criticizing the U.S. at that time was essential for anyone committed to human dignity and freedom. Activists and organizations opposed U.S. policies on human rights grounds but did not doubt Al Qaeda was a terrorist group, did not support Al Qaeda, and did not justify 9/11 attacks. Currently, there is hesitation or denial to clearly label attacks against Israeli and foreign civilians (also foreign citizens were victimised during the October 7 attack). Some even support such attacks as they denounce Israel for unjust, criminal, genocidal, etc. policies. This is wrong from a moral, ethical, and legal point of view, creating a dangerous precedent for the protection of civilians. Condemning Hamas does not equate to denying the right of Palestinians to life, dignity, freedom, security, and prosperity. Rather, it acknowledges that the end does not justify the means, even in war, or resistance.

The word “fluidity” could very well describe the security landscape 24 years after 9/11. There are too many rapidly shifting ideologies that are able to mobilize people. Security threats do not fit into fixed ideological boxes. There is easily accessible operational knowledge, expertise in weaponry or explosives is no longer a prerequisite for conducting an attack, and traditional security red lines have become obsolete. Frontiers do not mean anything when it comes to spreading propaganda and instigating hate online. Around the world, conflicts pop up, wars expected to finish soon still linger, and individuals once labelled as terrorists become legitimate political actors, accepted by the international system that forgets their murderous past. Organized crime groups are put on terrorist group lists so that terrorism laws (and the exceptional investigative power they give to authorities) apply. Finally, terrorism in the eyes of the beholder. Simply put: “It is not terrorism, if it is what the side I support did”. This fluid and fragmented landscape 24 years after 9/11 poses a great challenge for effective security and counterterrorism strategies, raising the level of risk and uncertainty that security experts and practitioners must address.