If a mysterious alien ray swept every gun off the North American continent tomorrow, very ordinary and low-skilled militants could still perpetrate horrendous violence quite comparable to last month’s Orlando attacks. In understanding and forestalling terrorist threats, access to weaponry is only one consideration out of a great many, and that fact is crucial to contemporary political debates.

But without guns, without so-called “assault weapons,” how could terrorists kill innocents in large numbers? One answer to that question comes from the Chinese city of Kunming, where in 2014 a group of eight Islamist militants from the Uighur people stormed the local rail station, killing 29 civilians. As private access to firearms is extremely difficult in China, the killers used long bladed knives, and used them to devastating effect. That tactic has been repeated, and some horrible Chinese “spectaculars” have reached international attention. Last year, the same Uighur movement attacked a Xinjiang coal mine, reportedly killing 50 workers.

Such mass knife attacks occur quite frequently in China, and by no means always for political motives. Still, the fact that any tactic has been so successful in one country attracts the attention of terrorist social media, such as the Islamic State publication Inspire, which brings them to global attention. IS especially recommends that followers around the world should use whatever means available to attack and kill unbelievers, and if guns and explosives are not easily found, then knives are quite acceptable.

Knife attacks have one major drawback for terror groups, namely the large numbers of people needed to inflict mass casualties. Mobilizing a group of eight attackers is difficult without a high danger of penetration and exposure. Other forms of non-traditional violence, though, can easily be committed by solitary lone wolves, and for that reason they are warmly advocated by IS and al-Qaeda.

The main weapons in question are vehicles, and the U.S. was the scene of one pioneering experiment in this form of terror. In 2006, an Afghan immigrant named Omeed Aziz Popal used his SUV to attack civilians in the San Francisco Bay area, killing one and injuring nineteen. His intentions were very clear: as one observer remarked, “He was trolling for people.” After hitting his victims, he returned to run over their prone bodies. Don’t worry if you have never heard of the crime, which was poorly reported, and in such a way that made virtually no reference to the driver’s ethnicity or religious background. The same year, Iranian Mohammed Reza Taheri-azar used his SUV to attack passers by on the campus of the University of North Carolina at Chapel Hill, injuring nine. The driver cited 9/11 pilot Mohammed Atta as his special hero.

If such attacks have not recurred in the United States itself, they have happened repeatedly in other countries, with the clear implication that tactics and methods are being developed through trial and error, awaiting full scale deployment. By far the commonest venue for these assaults has been Israel, presumably because militants there find it all but impossible to obtain guns or explosives. Vehicles, though, are much easier, and Palestinian guerrillas have used cars and also heavier machines such as tractors and bulldozers. Jerusalem alone has witnessed several such attacks since 2008, each with a number of fatalities. Uighurs (again) have used vehicles to ram crowds in Beijing.

2014 marked a turning point in this saga, when IS propagandist Abu Muhammad al-Adnani urged an all-out campaign of lone wolf violence. Find an unbeliever, he said, “Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him.” Multiple vehicle attacks occurred around that time. A man yelling “Allahu Akbar!” drove down eleven pedestrians in the city of Dijon, and the very next day, Nantes witnessed an almost identical attack by a separate militant. Also in 2014, a recent Islamic convert in Quebec used his car against two members of the Canadian military.

So far, the most striking thing about these lone wolf vehicular attacks is just how relatively small the casualties have been, but that could change very easily. It would be easy to imagine drivers choosing denser crowds, during busy shopping seasons or major sporting events. In this scenario, long lines of fans or shoppers or travelers represent a target rich environment. On such occasions, a determined driver not afraid of being killed could easily claim twenty or more fatalities.

Whatever else we might say about limiting access to firearms (even assault rifles), such a policy of itself would do nothing whatever to prevent these kinds of low-tech violence. The solution lies in efficient forms of intelligence gathering, monitoring and surveillance, combined with psychological profiling. The danger with such methods is that they will not pick up every potential assailant, while running a serious risk of producing lots of false positives, aggressive blowhards who in reality will never commit a crime. Just how to walk that particular tightrope, between effective prevention and respecting rights to free speech, is going to offer a major challenge to law enforcement agencies of all kinds.

And yet again, it would be very useful if our political leaders felt able to speak the name of the actual cause for which all those murderous guns and knives and cars are being deployed. Perhaps that is too much to hope.

Philip Jenkins is the author of The Many Faces of Christ: The Thousand Year Story of the Survival and Influence of the Lost Gospels. He is distinguished professor of history at Baylor University and serves as co-director for the Program on Historical Studies of Religion in the Institute for Studies of Religion.