In a video that has now been deleted from YouTube, a camera pans across a desert skyline before alighting upon a young man in the familiar regalia of the modern jihadist: fatigue pants and army boots, an ammo belt across his chest and an AK-47 at his side. “March forth with your weapons and defend the fronts in Syria and Iraq,” he says, his timbre and disposition suggesting some amount of media training. “With only a few of our soldiers in we are having an outsized impact,” he adds, looking directly into the camera. His extremist group’s logo flashes across the screen: “What Are You Waiting For?”

It’s a call that many angry young men have answered in recent years by making the journey to Syria to take up arms against all sorts of enemies: Bashar al-Assad, the United States, the Russians. It is also one that has become more technologically sophisticated. The clip of the young mujahideen, which was uploaded in early November, wasn’t a traditional recruitment video, but an extremist version of a Kickstarter campaign, with the goal of signing up new fighters over the anonymous Telegram app. The group behind it wasn’t al-Qaeda or ISIS, but an umbrella group called the Levant Liberation Committee, known in Arabic as Tahrir al-Sham, that was created as the result of a merger between the Qaeda-affiliated al-Nusra Front and other militant groups in Syria. The group’s fighters are younger and less religious; not tied to a geographic caliphate, like ISIS; and less interested in governance. They are, in other words, more nimble—and more dangerous. Call them ISIS 3.0.

As a diplomat and scholar who has studied violent extremism, I’ve seen firsthand how the spread of Tahrir al-Sham’s message has alarmed Western intelligence agencies, how critical Internet technology has become to terrorist groups, and how vulnerable our infrastructure is to cyber attacks. With a limited number of dedicated actors, Tahrir could take down local, regional, or even national power grids. They could disrupt cellphone, G.P.S., and satellite communications. In a worst-case scenario, they could hack into government computers and publish all types of classified military and intelligence information, endangering Western agents and assets. Our postal and package delivery systems depend on SatLocaters that, if compromised, could bring America’s sprawling logistics network to a standstill. On their hidden Telegram channel, Tahrir militants have bragged about adapting drones to deliver explosives or biological agents, and once posted an encrypted video of their efforts.

Whether or not the group has staying power, they already know how to shape and deploy information to their advantage. Recently, after an initial crowdsourcing campaign had run for only six hours, Tahrir claimed to have recruited over a dozen young followers, including five from Germany. These were played up in subsequent postings directed at potential new recruits. This crowdsourcing approach, via Telegram’s end-to-end encryption channels, is difficult to detect, let alone censor. Their Dark Web social networks, unlike ISIS’s territorial holdings, cannot be seen by satellites or destroyed with bombs. Tahrir leaders operate on the principle, “The narrower the audience, the bigger the impact.”

This still-emerging digital battlefield is the least understood component of our ever-changing, 16-year war on terror. Like any start-up, Tahrir militants have learned from ISIS’s successes and failures on the battlefield, using multiple platforms to amplify their impact. While ISIS sent messages using a broadcast model, Tahrir has experimented with platforms like Sarahah (“Honesty” in Arabic), which allows users to send messages anonymously to one person. The app provides a honeypot approach for Tahrir, in which they can A/B test different messages to see what sticks. While governments are still trying to censor ISIS on Twitter, Tahrir is experimenting with an app that reaches more than 16 million young people and is the top download in over 25 countries, including Egypt, Jordan, and Lebanon. Tahrir can fail, quickly measure what resonates, and retool their pitch before the activity is detected by officials. Again, speed gives them the advantage.