A quarter-century after 9/11, Islamist terrorism no longer dominates headlines. But has the public really become less responsive to it? Many politicians, journalists, and scholars think so. But research by Amélie Godefroidt, Micha Germann, and Fernando Mendez suggests that Islamist attacks continue to shape political attitudes in Western democracies as much as they did two decades ago
In the aftermath of the terrorist attacks on 11 September 2001, research showed consistently that Islamist terrorism shifts public opinion. Citizens became more supportive of restrictive security policies, more hostile toward immigrants and Muslims, and more likely to rally around national identities and incumbent governments.
Over time, however, a new narrative emerged. Because countries such as the UK, France, Belgium, and the US experienced repeated Islamist attacks, many started to argue that terrorism had become normalised. When studies on more recent Islamist terrorist attacks sometimes found weaker or even null effects, scholars equally claimed citizens had become 'desensitised' to the phenomenon.
The idea sounds plausible. Psychological research shows that repeated exposure to violence can reduce emotional reactions over time. People may gradually stop responding with the same fear, outrage, or sense of threat. But most evidence for desensitisation comes not from real-world political violence, but studies of fictional violence in films or video games.
Are Islamist terrorist attacks in Western democracies frequent enough to have become 'normal'? Or do they continue to shape political attitudes?
This raises an important question: are Islamist terrorist attacks in Western democracies frequent enough to have become 'normal'? Or do they remain sufficiently rare, symbolic, and emotionally charged to continue shaping political attitudes?
To answer this question, we conducted the first large-scale test of whether public responsiveness to Islamist terrorism has truly changed over time. Our findings are now published in the European Journal of Political Research.
First, we used a meta-analytic dataset covering more than 170 studies and around 840 effect estimates published between 2003 and 2023. These studies examined how Islamist terrorism affects political attitudes in Western democracies, including attitudes toward security policies, immigration, authoritarianism, and national identity.
If there was desensitisation, we should observe a clear pattern: more recent studies should consistently report smaller effects.
If repeated exposure leads to desensitisation, citizens in countries with many prior attacks should react less strongly to new ones. We found little evidence for such a relationship.
At first glance, that seemed to be the case. Raw time trends suggested that reported effects had declined somewhat over time. However, previous studies differ considerably in the attacks they examine, the countries they focus on, and the methods they use. Once we accounted for these differences, the apparent decline disappeared. Rather than reflecting a broader process of desensitisation, the initial pattern was driven largely by the unusually strong effects observed in early US studies.
We also examined whether the number of previous attacks mattered. If repeated exposure leads to desensitisation, citizens in countries with many prior attacks should react less strongly to new ones. Again, we found little evidence for such a relationship.
Meta-analyses are powerful, but they also combine studies conducted in very different contexts. To address this limitation, we conducted a second study comparing the 2017 and 2019 London Bridge attacks.
The attacks shared many characteristics. Both took place in the same location and involved perpetrators linked to Islamic State. Both also occurred in recent years and during election campaigns in a country already exposed to multiple Islamist attacks. If desensitisation were real, we would therefore expect both attacks to generate relatively limited public responses, and especially the later attack to produce weaker reactions than the earlier one.
To measure public opinion shifts, we used data from a Voting Advice Application (VAA) used by tens of thousands of British voters before the 2017 and 2019 UK general elections. This allowed us to compare attitudes immediately before and after the attacks with unusually high precision.
Again, the result went against the desensitisation hypothesis.
Both attacks increased support for tougher security policies and more restrictive immigration policies. Both also strengthened in-group identification. And, most importantly, the effects were broadly similar in size across both attacks, and closely matched the effect sizes identified in the meta-analysis.
Overall, our evidence suggests that Islamist terrorism retains considerable political power in Western democracies. Even relatively small-scale attacks, such as the July 2026 attack during the Berlin Pride Parade, can still shape how citizens think about security, immigration, and belonging. These findings challenge an increasingly popular assumption in public debate and academic research.
In sum, Islamist terrorism may no longer produce the same shock effect associated with 9/11 or the 2005 London bombings. But that does not mean citizens have become politically indifferent to it. One of the clearest patterns in our study is not temporal decline, but heterogeneity: some attacks generate large political reactions, while others generate smaller ones. Understanding when and why remains an important task for future research.
Islamist terrorism may no longer produce the shock effect of 9/11 or the 2005 London bombings. That does not mean citizens have become indifferent to it
But while we may not yet know precisely when terrorist attacks will shift public opinion, our evidence shows that they still can. And when they do, the consequences can reach well beyond the immediate aftermath of an attack. Indeed, previous research shows that by shifting public opinion, terrorist attacks can influence election outcomes, motivate restrictive policies that compromise civil liberties, and reinforce extremist narratives.
The legacy of 9/11, then, is not simply that terrorism transformed Western politics a quarter-century ago. It is that, even 25 years later, terrorism retains the capacity to move public opinion and, through it, democratic politics.
