Islamic State forces have begun weaponizing small commercial drones. And in response, the US military has deployed to the Middle East an undisclosed airborne electronic-warfare system. In other words, drone-killing planes.
Perhaps borrowing a tactic from Hezbollah—which in August released a video depicting one of the militant group's small, quadcopter-style drones dropping a small explosive device on rebel fighters in Syria—ISIS has taken to booby-trapping its own commercial-grade unmanned aerial systems, or UAS.
Enter the US's counter-drone planes. In October, American military forces in the region had at least two such aircraft types capable of jamming the radio signals used by insurgents to trigger bombs on the ground. The same aircraft could target an insurgent UAS and cut it off from its controller. The US anti-drone planes reportedly scored their first kill in October 2016.
Early that same month, pro-US Kurdish fighters in northern Iraq shot down an ISIS drone. As the Kurds dismantled the crashed robot, it exploded, killing two men. American military officials are increasingly worried about armed and booby-trapped UAS—in particular, their potential as terror weapons.
"If you're under attack from a UAS, even if it is militarily insignificant, [it] leads to mission degradation," Brig. Gen. Brian Killough, the Air Force's director of strategy, concepts and assessments, said at a robotics conference in Virginia in mid-October.
The Pentagon has launched several parallel efforts to develop counter-drone systems. The Marine Corps is developing a laser-armed truck for shooting down small flying robots. In April 2016, the Air Force asked the defense industry to work on a handheld drone-killing kit. "The defeat mechanism must disrupt or manage the control link between a commercial UAS and the pilot," the proposal states.
Military leaders tasked the Joint Improvised Explosive Device Defeat Organization, whose main job is developing technologies to counter roadside bombs, to also work on anti-drone systems.
At least one of the systems has already been deployed in the Middle East. On October 24, Air Force Secretary Deborah Lee James told an audience in Washington, DC, that the flying branch had recently "shot down" an ISIS drone using electronic measures. "Fairly quickly we were able to bring it down," James said, according to Air Force magazine.
The service was coy about the exact nature of the counter-drone system. Air Force spokeswoman Erika Yepsen told Air Force that two USAF intelligence, surveillance, and reconnaissance assets worked together to force down the ISIS drone near Mosul in less than 15 minutes.
Hezbollah's drone attack.
It's likely that the "electronic measures" the ISR aircraft deployed were radio-frequency jammers, similar to the kind that JIEDDO developed to protect ground forces from IEDs during the heights of the US occupations of Iraq and Afghanistan.
The jammers disrupt the radio signals that insurgents use to detonate bombs. The command signals that connect drones to their operators on the ground are similar to the detonation signals for roadside IEDs.
The Air Force's 43rd Expeditionary Electronic Combat Squadron, based in Kuwait, operates a small number of jammer-equipped EC-130H Compass Call planes with a primary mission to disrupt enemy radars and communications.
"From a non-kinetic standpoint, they have played a significant part in the fight against Da'esh," Col. Charles Bolton, commander of the 386th Air Expeditionary Wing, which oversees the 43rd EECS, said of the EC-130Hs. ("Da'esh" is a pejorative term for ISIS.)
The Navy's EA-18G electronic-attack jets, flying from the aircraft carrier USS Dwight D. Eisenhower—which arrived in the Persian Gulf this summer—can also jam radars and communications.
The Marines' UH-1Y and AH-1Z helicopters can carry a podded communications-jammer called Intrepid Tiger II. While the helicopters have been active in the coalition campaign against ISIS in Libya, it's unclear whether the same aircraft types were available in northern Iraq in October.
Moreover, the Marines generally don't refer to the UH-1 and AH-1 as "intelligence, surveillance and reconnaissance" aircraft.
Regardless of which aircraft type or types participated in the October shoot-down, it's clear that the US military is taking seriously the threat that Islamic State's killer drones pose—even if that threat is mostly psychological.