Back before GPS was ubiquitous, a couple decades ago, I thought it would lend itself all too well to sabotage or terrorism. Imagine sending out a fleet of miniature, autonomous Hindenburgs to burn down a dozen targets on a windless night, or dropping lawn darts from the sky.
The Russians figured this out, it would appear:
A precision attack does not need to deliver a massive warhead: it just has to ‘bring the detonator’ to a vulnerable target.
The Ukrainian SBU – the equivalent of the FBI – now believe that the destruction of a giant arms depot at Balakliya in eastern Ukraine in March was carried out by a small drone. The spectacular explosion and fire destroyed some seventy thousand tons of munitions with damage estimated at a billion dollars, though only one person was killed. This destruction is a graphic illustration of the threat posed by small drones, as many other high-value targets may be equally vulnerable.
Balakliya was said to be the largest ammunition dump in the world. Photographs of the site show wooden boxes of ammunition left in the open, making it a tempting target for an aerial saboteur. Several similar strikes have been carried out in Ukraine.
“This form of anti-materiel attack—though on a lesser scale—has already taken place at least two times in South-East Ukraine by Russian-linked forces utilizing weaponized UAS dropping incendiary bomblets,” says Robert Bunker, Adjunct Research Professor at the U.S. Army War College.
On 29th October 2015, the ammunition depot at Svatovo was hit. Some three thousand tons of ammunition went up, and 1,700 homes were damaged nearby.
This year, on the night of 17th February, an ammunition warehouse in Zaporozhye region was set on fire causing a series of explosions. The same tactics were used the next night at a storage site near Grodovka village in the Donetsk region, but this time the fires were put out. On 14th March a drone attacked another Ukrainian military facility near Donestsk, making three separate sorties and dropping two grenades each time according to Ukrainian military officials.
There had been a previous drone attack at Balakliya in December 2015, when small drones dropped at least fourteen grenades. The grenades started fires in the open storage areas, but the Ukrainian soldiers, showing considerable bravery, put out the fires. On that occasion one of the devices was recovered intact, and was identified as a Russian ZMG-1 mine grenade.
The ZMG-1 is a thermite charge, a specialist tool used for demolition by Russian special forces, which resembles the U.S. AN-M14 grenade. Grenades of this type burn rather than exploding, and are placed rather than thrown, as they must be in contact with the target. They are filled with a mixture of metal and metal oxide which react to produce extreme temperatures – something over 4,000 degrees Fahrenheit.
The AN-M14 can melt through a steel plate half an inch thick and is typically used to disable artillery. The ZMG-1 appears to have similar capability. The Ukrainian SBU have previously captured ZMG-1s in caches associated with Russian separatist groups, so they have such weapons, and ammunition dumps are a prime target.
“A weapons depot is such a good target for drones because incendiary device dropped from the drone only needs to act as fuse, using the materiel on the ground for the actual explosion,” says Ulrike Franke, a drone expert at the European Council on Foreign Relations.
This echoes the warning by T X Hammes of the Center for Strategic Research about a type of attack he calls ‘bringing the detonator’. Where there is a suitably vulnerable target, even a drone with a small warhead can do tremendous damage. It does not need to carry the explosive, because explosive is already there, it is just a matter of setting it off. This does not just mean ammunition dumps.
“Other infrastructure sites that would be particularly vulnerable to this form of attack would be those storing highly flammable substances such as fuel — especially aviation fuel,” says Bunker. “Commercial aircraft parked at an airport laden with fuel in their wing storage cells would also be very susceptible.”
Hammes also mentions parked aircraft as a target. Sites storing quantities of liquified natural gas or petrochemicals, fuel depots and similar locations could be similarly susceptible to such attacks. Storage tanks of other dangerous chemicals might not explodes and burn, but if ruptured they could still have catastrophic effects. Th accidental release of methyl isocyanate gas from a plant on Bhopal in 1984 caused over three thousand deaths. Any risk of a similar incident is likely to result in the evacuation of a wide area as a minimum, even if there are no casualties.
Small drones are readily available over the internet. Unlike earlier generations of radio-controlled aircraft, they are easy to use, and a beginner can fly one out of the box. Grenades of the sort dropped by drones in Iraq and Syria may be hard to acquire outside of a war zone, but thermite is another matter. It is easy to make, and can be legally purchased in the US, UK and elsewhere. Terrorists may have trouble making their own explosives, and often get caught in the process, but they can acquire thermite without attracting attention.