As if Syrian regime forces, Russian airstrikes, and internal squabbling weren’t enough to worry about, Syrian rebels have apparently now come under attack from Hezbollah drones dropping bombs.

On Aug. 9, the Iran-backed Lebanese militant group posted a video online purportedly depicting a commercial, quad copter-style drone dropping small explosive devices at alleged rebel positions in Aleppo, a major opposition-held city in northern Syria.

The 42-second video, apparently a compilation of footage shot by the attacking drones themselves, seems to show the robots hovering a few hundred feet over vehicles and structures as small blasts scatter fragments and send smoke and dust billowing into the sky.

In the third and final attack, the grenade-size munitions themselves—possibly Chinese-made MZD-2 artillery submunitions—are visible falling away from the drone. A person on the ground spots the bombs falling toward them and flees the targeted structure moments before the explosives detonate.

Hezbollah has deployed thousands of fighters to Syria to help bolster troops loyal to Syrian president Bashar al-Assad. Hezbollah fighters lack heavy vehicles and weaponry but have moved quickly to adopt small, inexpensive drones for surveillance and attack missions.

As early as November 2004, Hezbollah sent Iranian-supplied Mirsad drones into Israeli airspace on spy missions, catching Israeli air defenses off guard. Shortly thereafter, Hezbollah leader Hassan Nasrallah proclaimed that the Mirsad could penetrate “anywhere, deep, deep” into Israel while carrying more than 200 pounds of explosives.

It was a bold claim for the time. The United States was the first country to deploy a modern, armed drone—the Predator—in 2001. For several years, America possessed a virtual monopoly on weaponized flying robots.

Nasrallah was perhaps exaggerating, but he wasn’t bluffing. In August 2006 during Israel’s brief, bloody war with Hezbollah in Lebanon, the militant group launched three explosives-laden Ababil drones toward Israeli territory. Israeli jet fighters shot down all three robots.

Hezbollah’s current armed drones represent a departure from the group’s previous concept for drone operations. The Mirsads and Ababils were, in a sense, strategic terror weapons, meant to cross borders and strike fear in enemy populations.

The submunition-armed drones that Hezbollah has deployed over Aleppo are, by contrast, strictly tactical. Hovering, commercial-style drones can fly only a short distance away from their operators and, under the best of circumstances, can haul only a few pounds of payload. But what the drone-copters lack in sheer power, they make up for in stability—hence their ability to accurately drop an unguided submunition.

They’re also cheap, easy to procure, and simple to operate. For all but the most impoverished military force, a $200 quadcopter is disposable. And that means the type could crop up again not only in Syria, but also on battlefields all over the world—as a bomber... or as a bomb itself, rigged to explode on command.

The Pentagon, for one, is assuming that small, cheap, weaponized drones will soon pose a significant danger to American troops. “I personally believe that the unmanned platform is going to be one of the most important weapons of our age,” U.S. Navy Capt. Vincent Martinez, who oversees technology development for the fleet’s bomb squads, told Defense News last year.

Martinez said he was doubly worried about drones crashing or landing while hauling improvised explosive devices or other munitions that the robot or its operator might trigger as bomb-disposal troops approach. “I’m going to have to start thinking not only about how I defuse the payload but how I defuse the platform,” Martinez said. “When I walk up on that platform, is it watching me, is it sensing me, is it waiting for me?”

The U.S. military is preparing its drone defenses. On Aug. 11, the fringe-science Defense Advanced Research Projects Agency asked for researchers and companies to propose technologies that might “detect, identify, track and neutralize these [drone] systems on the move, on a compressed timeline and while mitigating collateral damage.”

One private firm has already begun marketing one such tech. In March, OpenWorks Engineering began offering its SkyWall 100—in essence, a bazooka that fires a drone-entangling net—as a non-destructive robot-countermeasure.

The U.S. Marine Corps, for one, is signaling that it won’t hesitate to simply blow up drones in midair. Skipping ahead of DARPA’s own solicitation, the Marines recently announced plans to fit a drone-blasting laser cannon to its new armored vehicle starting in 2022.

But with Hezbollah already lobbing grenades from quadcopters in Syria, the non-state perpetrators of small-scale drone warfare have the jump on the world’s established armies and their lumbering bureaucracies.

At present, weaponized drones are way ahead of defenses against weaponized drones. If you shoot one down, another might quickly take its place. And once it drops its bomb, you can only do what that unfortunate figure can be seen doing at the end of Hezbollah’s new video—run.