I used to feel compelled to write something on 9/11. Some of this was just to participate in the discourse, some out of fear that failure to do so would mean moving on and forgetting. In 2009–back when I provided free labor for The Huffington Post–I wrote this on the shadowy but still serious threat posed by al-Qaeda. More recently, I wrote this on the failure of security studies to adapt in response to 9/11.

But I wasn’t sure what to say this year. It’s partly an issue of sensory overload. I’ve started and stopped multiple posts in the past few weeks as new events come up before I have a chance to comment on the previous one. But it’s also because of the unclear nature of terrorism in 2025.

The post-9/11 consensus

9/11 was not the generation-defining event some thought it would be–the 21st century Pearl Harbor. But it did provide some clarity. Al-Qaeda was a threat to both the United States and the Muslim countries al-Qaeda claimed to champion. There was debate about the logic behind its actions and how best to respond, but except for a few radical outliers most agreed al-Qaeda were not the good guys. When there was disagreement, it was over the extent to which the US brought 9/11 on itself.

This isn’t to say everyone was united in social harmony. The Bush Administration used the attacks to hurt Democrats politically and justify the Iraq war. And anti-Muslim attitudes and incidents increased in the United States. Even as a valuable consensus on addressing the threat emerged, it still was misused and led to abuse.

Focus on al-Qaeda waned with the imminence of its threat, but then the Islamic State emerged. This too was seen as a transformative threat to the Middle East at least, but the state system pushed back and the group was defeated as a territorial force.

Both al-Qaeda and the Islamic State still exist, and still kill people, but their ability to directly threaten US society is greatly diminished.

Current uncertainties

Terrorism hasn’t disappeared, but it’s become less clear what it is and how to manage it.

Even as the Islamic State faded, right-wing threats become more prominent. There were a number of lone wolf attacks by right-wing individuals that would fall under the definition of terrorism. Violent right-wing groups like the Proud Boys and the Boogaloo movement have become active. And there were recent horrific acts like the assassination and planned attacks on Democratic politicians in Minnesota.

But there has also been left-wing violence. The killer of the healthcare CEO was motivated by anger at the US healthcare system. The man who shot Congressman Steve Scalise in 2017 had plans to attack other Republicans. And it is possible that the person who killed Charlie Kirk was motivated by opposition to Kirk’s right-wing beliefs. Here in Vermont, synagogues have been vandalized and threatened with anti-Israel messages.

And many of these incidents are less cut and dry than activities of al-Qaeda and the Islamic State.

I believe lone wolf attacks still count as terrorism, but some think they need to be attached to a group. Beyond that, the motivation is less clear for lone wolf actors, as is the extent to which they are building into a true right-wing wave of terrorism.

The Proud Boys are violent and extremist, but much of their violence tends to be “spontaneous,” hate crimes and riots like the January 6th attack on the Capitol. Some may debate whether this counts as terrorism; I consider January 6th terrorism, but there is a real question whether disorganized political violence should be considered terrorism.

The line between assassination and terrorism is also unclear. If someone wants to eliminate a particular person, rather than send a message to members of that person’s group or political movement, it may not count as terrorism. At what point is, for example, killing a healthcare executive terrorism against those who benefit from capitalism?

There is also the question of “stochastic terrorism,” the idea that a prominent figure may inspire violence by members of a movement with their rhetoric. To what extent are nonviolent speakers responsible for lone wolf attacks or disorganized political violence? This is mostly addressed to the right, but comes up with the left as well, as seen in the use of pro-Palestine rhetoric to threaten US Jewish groups.

And there is also the more nihilistic violence we keep seeing. Violence that may have meaning to the person committing it, but it’s unclear from the outside. Some have characterized the Minneapolis church attack as such violence. More terrorist attacks are difficult to place under any ideology. The seemingly incessant school shootings sometimes have warped political justifications, but often just seem to be violence for violence’s sake. These are clearly connected to the general threat of terrorism, but in what way? Do they feed into it? Is it a separate category?

And the consensus on addressing terrorism has fractured. Post-9/11, liberals and conservatives were agreed on the need for action, but they differed on what to do. Liberals tended to champion the preventive steps that emerged towards the end of the Bush Administration and were expanded by President Obama (I wrote about them in my latest book). That’s not the case now. I don’t mean random people online praising one attack or another. The Trump Administration has very clearly moved to dismantle violence prevention programs, which affects terrorism, disorganized political violence, and nihilistic school shootings. As with cuts to the State Department, the logic is unclear, but it definitely indicates a de-prioritization of preventing this sort of violence.

Moving forward

So what do we do now?

I teach a Terrorism and Counterterrorism course in the spring, and am starting to think about what changes I’ll make to my syllabus. For contemporary terrorism I had done one session on al-Qaeda, one on the Islamic State, and one on right-wing extremism. Then I added a second session on right-wing extremism in which we watched and responded to a documentary. I’m not sure that’s the best way to approach this now.

Do we need full sessions on al-Qaeda and the Islamic State? In terms of their historical importance and lessons they can give on future transnational movements, the answer is yes. But with a limited number of course sessions, and other topics that need to be covered (the first half is examples of terrorism and the second is academic and policy debates on explaining terrorism and formulating counterterrorism strategies) should I change this? Should the emphasis be more on contemporary right-wing threats, even if many of them do not count as terrorism? But then this risks turning a course on a specific topic–I emphasize the importance of defining terrorism well in the beginning–into a general course on political extremism.

This mirrors the broader policy and academic issues. How do we arrive at a consensus on what this political violence means, and where it is coming from? Should we even do that? Was terrorism always a flawed concept (I’ve been debating this since grad school)?

My take reflects my concluding lecture in my latest Terrorism and Counterterrorism course. I noted a “terrorism chic” seems to be returning, in which people on every side see terrorism as cool and sometimes necessary due to the deep divisions in our society. But no matter how wrong the other side is, and how unforgiveable their actions, terrorism–and political violence in general–inherently dehumanizes people.

I’ve started and deleted this final paragraph a few times, and don’t think I’ll have a good ending. But I think what we need is solidarity. Just as people pointed out that the victims of 9/11 included all religions, ethnicities and nationalities, so too should we point out the victims of contemporary terrorism (or political violence if you’d prefer that term) affect everyone. So we should all unite against it.