With a body count of 14 (excluding the perpetrator), Wednesday’s act of terror in New Orleans is now the deadliest vehicle-ramming attack in American history. The record was previously held by Sayfullo Saipov, who in October 2017 drove a pickup truck into a crowded cycle path along the Hudson River in New York, killing eight people.

Like Saipov, Shamsud-Din Jabbar, the perpetrator of the New Orleans attack, had professed allegiance to Isis; indeed, he attached the distinctive black flag popularised by the group to the pickup truck he used. In the coming weeks, the media and the legion of online sleuths who have come to distrust it will frantically rake over Jabbar’s life story in an effort to discover how he went from being a reserved type who “kept to himself” to the sort of dead-eyed fanatic who could murder scores of people in cold blood.

No less predictably, extremism experts will do what they always do in the wake of an Isis-related attack, which is to sound the alarm about how the group never really went away, despite its near-total destruction in March 2019, and how it still represents a serious threat. While it would be foolish to write off Isis, it seems unlikely that the New Orleans attack will spark a new wave of jihadist terror in the West, given that the group no longer commands any significant territory and long ago jettisoned its ideological primacy within the global jihadi movement.

The more likely scenario portended by Jabbar’s actions is instead more vehicle-ramming attacks, regardless of the animating motivation. This is because the tactic itself has a contagious quality which appeals to all kinds of would-be-murderers — from jihadists to incels to white supremacists to the eternally aggrieved and the mentally unhinged. As an approach to killing, it is cheap, effective, and requires no particular competence other than the ability to drive in a rudimentary way.

It is surely no accident that the New Orleans attack follows so quickly on the heels of the ramming attack in Magdeburg, Germany last month. These events tend to happen in clusters, and Jabbar is almost certain to have at least known about it. It is a well-documented fact, which will surprise no one, that would-be-murderers are deeply interested in the theory and practice of mass-murder. Watching or reading about how the Magdeburg attack unfolded may have given him the impetus to “go postal” himself. Isis, for its part, has been inciting followers to launch vehicle-ramming attacks since September 2014, when the group’s then-spokesman Abu Muhammad al-Adnani explicitly mentioned it alongside a host of other killing methods.

In a paper on vehicle-rammings published in 2019, the academics Keith Hayward and Vince Miller asked why these motorised crimes had only now been adopted by everyone from jihadists to Right-wing lone-wolf killers, despite the availability of automobiles for decades. Their answer, roughly, was that it is not ideology, incitement or a lack of violent alternatives that connect the perpetrators of vehicle-ramming attacks. Rather, it is the very spectacle of a car ploughing into defenceless and terrified bodies that serves to inspire further such terrorism. More recent research broadly supports this conclusion, and documents the striking way in which vehicle-rammings, particularly since 2017, are clustered so closely together.

Whether or not the horrific violence in New Orleans inspires further Isis attacks in America and other Western countries remains to be seen. There is certainly no shortage of desperate or depressed loners who might wish to latch onto the jihadist group’s faded glory to escape their marginality, if only for a fleeting moment. But it’s almost certain that Jabbar will prompt another, near-identical spectacle of motorised horror, whatever the propelling motive. We just don’t know when or where it will transpire next.