The horrific recent attack in San Bernardino has attracted a good deal of bafflement from media and government alike. What kind of Islamist assault was this? If Syed Farook and Tashfeen Malik were not acting together with a “real” terror group or network, were they really terrorists? Were they taking orders from some mysterious head or group, still unidentified? Actually, there is an easy and unsettling answer to all these questions. Yes, they certainly were terrorists, and they were following one of the most dangerous tactics known in that world, “leaderless resistance.” The fact that U.S. law enforcement is still so startled by this method, and so utterly unprepared, is deeply alarming.

Do not for a second think that by using the term “resistance,” I am justifying these disgusting crimes, or comparing them to guerrilla resistance movements. Rather, I am using a well known technical term, albeit one with a very odd history.

Amazingly, the story goes back to the U.S. ultra-Right in the 1980s. Far Rightists and neo-Nazis tried to organize guerrilla campaigns against the U.S. government, which caused some damage but soon collapsed ignominiously. The problem was the federal agencies had these movements thoroughly penetrated, so that every time someone planned an attack, it was immediately discovered by means of either electronic or human intelligence. The groups were thoroughly penetrated by informers.

The collapse of that endeavor led to some serious rethinking by the movement’s intellectual leaders. Extremist theorists now evolved a shrewd if desperate strategy of “leaderless resistance,” based on what they called the “Phantom Cell or individual action.” If even the tightest of cell systems could be penetrated by federal agents, why have a hierarchical structure at all? Why have a chain of command? Why not simply move to a non-structure, in which individual groups circulate propaganda, manuals and broad suggestions for activities, which can be taken up or adapted according to need by particular groups or even individuals?

To quote far Right theorist Louis Beam,

Utilizing the leaderless resistance concept, all individuals and groups operate independently of each other, and never report to a central headquarters or single leader for direction or instruction … No-one need issue an order to anyone.

The strategy is almost perfect in that attacks can neither be predicted nor prevented, and that there are no ringleaders who can be prosecuted. The Internet offered the perfect means to disseminate information. Already in the mid-1980s, the neo-Nazi networks were pioneering early adapters of the electronic bulletin boards that preceded the World Wide Web.

In 1989, Rightist intellectual William Pierce published a book that provides a prophetic description of leaderless resistance in action. Hunter, published in 1989, portrays a lone terrorist named Oscar Yeager (German, Jäger) who assassinates mixed-race couples. The book is dedicated to Joseph Paul Franklin, “the Lone Hunter, who saw his duty as a white man, and did what a responsible son of his race must do.” Franklin, for the uninitiated, was a racist assassin who launched a private three year war in the late 1970s, in which he murdered interracial couples and bombed synagogues. The fictional Yeager likewise launches armed attacks against the liberal media, and against groups attempting to foster good relations among different races and creeds.

Central to the book is the notion of revolutionary contagion. Although the hero (for hero he is meant to be) cannot by himself bring down the government or the society that he detests, his “commando raids” serve as a detonator, to inspire other individuals or small groups by his example. “Very few men were capable of operating a pirate broadcasting station or carrying out an aerial bombing raid on the Capitol, but many could shoot down a miscegenating couple on the street.” He aimed at the creation of a never-ending cycle of “lone hunters,” berserkers prepared to sacrifice their lives in order to destroy a society they believe to be wholly evil.

Politically, the U.S. ultra-Right was too weak in the 1990s to follow Pierce’s model, and the movement never fully recovered from the Oklahoma City attack. But the Hunter tactics live on, precisely, in the modern Islamist world, and specifically in the influence of Yemeni-American propagandist Anwar al-Awlaki, who was killed by U.S. action in 2011. Reading texts from al-Qaeda’s online magazine Inspire, we so often hear what sound like direct echoes of Pierce, and especially of leaderless resistance.

That connection is actually not hard to explain. We know that al-Awlaki spent the 1990s in the U.S., where he would have had easy access to the rich array of paramilitary books and manuals circulated by far Right and survivalist mail order firms, which also sold anti-Semitic tracts. Both kinds of writing would have appealed to a budding jihadi. If he dabbled at all in this subculture, he would very soon have encountered the books of Pierce, who was a best-seller in these catalogues. Particularly in the early nineties, Hunter was the hottest name in this literary underworld. If not Hunter itself, al-Awlaki would certainly have heard discussions of leaderless resistance, which was all the rage on the paramilitary Right in those years.

In light of that, look at the domestic terror attacks in the U.S. in the past decade, all of “lone wolves” or of tiny hermetic cells, made up of siblings or married couples. Think of the Tsarnaevs in Boston, of Nidal Hassan in Fort Hood, of Muhammad Youssef Abdulazeez in Chattanooga, and now of Farook and Malik in San Berndardino. Think also of the many instances—never fully catalogued and collated—of Islamist “lone wolves” driving cars into crowds. Call it “self-radicalization” if you must, but what we have in progress, in the contemporary United States, is a textbook example of a Hunter-inspired campaign of leaderless resistance.

What that means is that virtually none of the counter-terror tactics currently deployed by U.S. agencies have the slightest relevance to detecting or preventing future attacks. You can’t track leaders because there aren’t any, you can’t infiltrate the group or turn participants, and all the propaganda and terror methods needed are on the Internet. They are getting their training and propaganda online from Qaeda sites like Inspire, and more recently by the ISIS/Daesh magazine Dabiq.

For the sake of argument, let us accept the optimistic view that 99 percent of American Muslims flatly reject terrorism. Not counting any future migration, that would still leave one percent of the whole, or some 30,000 potential Islamist militants. That is enough people for 10,000 leaderless cells.

Addressing this issue would seem to be the absolute number one priority of U.S. law enforcement in the coming years. Shall we begin, at least, by naming the enemy?

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.