"As both Islamic State and Amazon have shown, small drones are an efficient way of carrying a payload to a target."
On the night of January 5, a swarm of explosives-laden small drones, apparently controlled by Syrian rebels, attacked two Russian bases in western Syria, the Kremlin confirmed on Thursday. Authorities claim that Russian defenses destroyed or disabled all of the drones before they inflicted any damage on the bases.
But the threat from small, cheap, numerous, and armed unmanned aerial vehicles isn't going away. The next swarm could be bigger and more dangerous.
Ten of the drones, which the Kremlin described as "aircraft-type," assaulted Khmeimim air base, where Russia stages most of its air power in Syria. A rebel artillery attack on Khmeimim on December 31 reportedly damaged or destroyed several Russian warplanes.
Meanwhile, three drones attacked Russian facilities at the nearby port of Tartus. Russia intervened in the Syrian civil war on the side of the Syrian regime starting in late 2015.
Each of the drones carried 10 one-pound bombs under its wings, the Kremlin said. The Russian defense ministry published photos of, it claimed, intact bombs and drones Russian troops captured during the assault.
The Kremlin claimed that a Pantsir-S air-defense system shot down seven of the drones while Russian electronic-warfare specialists hacked six of the UAVs and ordered them to land, but three were destroyed when their explosives detonated. The Russian army recently commissioned its first dedicated counterdrone unit equipped with powerful electronic jamming systems.
Read more: Russia Army Gets Specialized Drone-Hunters
For years, Syrian rebels and Islamic State militants have been using consumer-style drones costing around $1,000 apiece to spy on rival forces, drop small bombs and conduct suicide attacks while carrying explosives.
"As both Islamic State and Amazon have shown, small drones are an efficient way of carrying a payload to a target," Nick Waters, a former British Army officer and independent military analyst, told me. "Whether that payload is your new book or several hundred grams of explosive is up to the sender."
Russian troops were aware of the growing drone threat. "The Russian side registered that insurgents started using drones of a new type and modifications," Maj. Gen. Alexander Novikov, head of the Russian general staff's Office of UAV Development, told reporters on Thursday.
Where previously insurgents mostly deployed off-the-shelf quadcopter-style drones, the drones in the January 5 attacks were custom-built winged models powered by lawnmower or motorcycle engines and could carry more munitions than can a typical quadcopter.
Novikov said all 13 drones launched from the same location no more than 60 miles from the target bases and flew toward preplanned coordinates, where they'd been programmed to drop their bombs.
The precise GPS coordinates necessary for an accurate attack indicated that the drone operators sent some of their UAVs on reconnaissance runs before launching the full attack, Novikov said.
The Kremlin expects more drone attacks. "The fact that terrorists have received assembly technology and programming technology is the evidence that this threat stretches far beyond the Syrian borders," Novikov said.
"Such lethal drones can be applied by terrorists in any country, targeting not just military objects."
The drones grow more dangerous as they become more numerous. It's unclear how many UAVs it might take to overwhelm the defenses at facilities such as Russia's in Syria, but it's a safe bet that the swarm would cost less than $15 million, the cost of a Pantsir-S system. Militants probably can add drones more easily than governments can add air-defenses.
"In nature think how each ant is not all that smart, but they do amazing things together," Peter W. Singer, a drone expert and author of Wired for War, told me. "That's what you have here with robotic swarming. It's a huge deal."
Get six of our favorite Motherboard stories every day by signing up for our newsletter.