Should we worry about ISIS threats to attack US, British cities?

The ISIS terrorist group’s “cyber caliphate” has called on its followers to again engage in the sort of lone wolf or wolf pack terrorism that has become its hallmark, with a series of chilling messages targeting San Francisco, New York and London that were recently released. One poster reads, “Don’t spare none [sic]. Kill them all. It is now time to rise. Slit their throats. Watch them die.” Another poster features a flag-waving terrorist in a suicide bomb vest walking down a crowded street in Manhattan, urging ISIS followers to “slaughter them all.” 

A third poster features a burning Westminster Abbey and Big Ben in flames, while a fourth poster warns: “O crusaders in London and everywhere, do you think we have failed? Do you think the supporters of the Islamic State gonna [sic] be surrender? Be know [sic], O crusaders, the soldiers of [sic] caliphate is everywhere and will attack immediately in your countries.”

The messages on the posters — delivered by the app Telegram from followers in Indonesia — are certainly concerning given ISIS followers’ penchant for beheading their victims and carrying out mass-casualty suicide bombings. The posters clearly are a call for internet “jihadified” terrorists to carry out the sort of suicide-bombing bloodshed that ISIS bombers have brought to the streets of Paris, Brussels and, most recently, in Sri Lanka this Easter. 

Calls for self radicalized, armchair jihadists to carry out attacks on their own are ISIS’s unique way of galvanizing “soldiers of the caliphate” to kill “crufixers” in Western lands defined by ISIS in medieval Arabic warfare terms as the dar al harb (the realm of war) and dar al kufr (realm of the infidel). ISIS spokesman Mohammad al-Adnani infamously called on followers living among “infidels” to act on their own, stating:

“If you can kill a disbelieving American or European — especially the spiteful and filthy French — or an Australian, or a Canadian or any other disbeliever from the disbelievers waging war, including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah and kill him in any manner or way, however it may be. … 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.”

Internet-enabled radical Muslims have heeded such calls in Europe and in America, and these “self-starter” terrorists do not necessarily need to be members of a trained sleeper cell, such as the 9/11 al Qaeda Hamburg cell, to wreak havoc. There have been three notable self-starter ISIS-inspired terror attacks in the U.S., including the June 2016 attack by an Afghan American named Omar Marteen who mowed down 49 people in an Orlando gay nightclub. There was the case of two terrorists, acting on Adnani’s message, who carried out a mass shooting in San Bernardino, Calif., in an assistance center on Dec. 2, 2015. And there was the case of an internet-radicalized Uzbek who plowed a truck into a crowd of bicyclists in Manhattan, killing eight, on Halloween 2017. 

But before one cancels travel plans to London, San Francisco or New York, the latest ISIS calls for holy mayhem should be put in perspective. While the resilient ISIS terror movement is far from being “wiped out” or “obliterated” — as President Trump has claimed, just because it lost its physical state  — its ability to incite terror attacks in similar online poster campaigns has been dismal.

ISIS’s most concentrated, but ultimately unsuccessful, effort to galvanize lone wolf attacks came during the 2018 FIFA World Cup in Russia. ISIS followers launched a veritable blitz of slick posters featuring chilling images of terrorists beheading such famous soccer players as Cristiano Ronaldo and Lionel Messi and carrying out sniper and bombing attacks on packed stadiums. But despite the wave of poster threats that dissuaded many from traveling to Russia for the soccer finals, no terror attacks took place in the various World Cup stadiums. 

ISIS also launched waves of jitters-inducing posters that aimed to incentivize its U.S. followers to attack “soft targets” in New York and Washington, D.C., during Christmas and New Year’s Eve in 2017 and this year’s Fourth of July celebrations. A poster released just before July 4th by ISIS followers was typical of this genre, with an image of a terrorist with a grenade-launcher in front of a burning White House. Another one warned New Yorkers: “Know O Crusader infidel that you — Allah willing — will soon be pursued in your own homeland. You will be pursued in the streets and in the alleyways and you will burn by the flames of the IEDs; only this time you will be feeling the pain of what you have inflicted for decades upon the Muslims, of killing, burning, destruction, and displacement in refugee camps.”   

These posters, and calls for mayhem, certainly represent the hopes and aspirations of the graphic artists and ISIS “cyber jihadis” who create them with the hope that they will spread fear — and perhaps even awaken an armchair jihadist to get out of the chair and fulfill Adnani’s dark order to kill infidels. But such online poster campaigns for terrorism have not been translated into reality thus far in New York or Washington. 

No terrorism expert would write off such threats as mere bluster, especially in light of recent FBI arrests of ISIS adherents in Arizona and Indiana, who were planning exactly the sort of DIY mayhem ISIS has called for. But recent history would indicate that the sick posters exhorting lone wolves to attack in San Francisco, New York and London are more aspirational than actionable threats.  

Brian Glyn Williams is a professor of Islamic history at the University of Massachusetts, Dartmouth and author of “Counter Jihad: The American Military Experience in Afghanistan, Iraq and Syria” and “The Last Warlord.” He worked for the U.S. Army and the CIA’s Counterterrorism Center in Afghanistan. Follow him on Twitter @BrianGlynWillms.