The modern equivalents  of  [improvised weapons] are more high-tech and, like Aleppo’s hell cannons, far deadlier...Any side that begins with a technological advantage will see it erode quickly as the underdogs improve their improvisation capabilities… [H]ell cannons are being mounted on vehicles and fitted with recoil springs to absorb the launch explosion. This improves stability, which in turn enables greater accuracy with follow-up shots. Some designs are no longer fired by lighting a fuse, but at a safe distance with a car battery wired to the propellant charge. Bigger cannons heave oxygen cylinders and, astonishingly, even large household water-heaters packed with enough explosives to destroy a cluster of buildings.

The ominous consequences have led America’s Defence Advanced Research Projects Agency (DARPA), an arm of the Pentagon, to try to keep up with developments by soliciting worldwide for new ways to make weapons using commercially available materials and technologies. More than 20 experts are now reviewing hundreds of submissions. To better assess the risks, some of the most promising designs will be built as prototypes and tested…[DARPA Improv]

Improvised weaponry typically is not as fearsome as that made by defence companies. But it is a lot cheaper and often effective enough… Despite receiving arms shipments from Iran and Russia, Syria’s regime still uses its own improvised “barrel bombs”—devastating devices made by filling oil drums with explosives and scrap metal….

Even defence firms are turning to more commercially available equipment to make weapons. Lasers used to cut and weld materials in industry, for example, are now so powerful that Boeing bought a 10kW model to put into its High Energy Laser Mobile Demonstrator (HEL MD), a system it has assembled for the American army to shoot down drones and incoming mortar shells by firing a laser beam at them. Just think of HEL MD as “a welding torch” with a reach of kilometres, says David DeYoung, head of the Boeing unit that built it. While the off-the-shelf laser is powerful enough for its role, IPG Photonics of Massachusetts is now selling a 20kW laser.

Smartphones are useful in making weapons. They contain GPS navigation and frequency-hopping technology, which transmits signals that are hard to intercept or jam (both were military developments). Other useful things inside include accelerometers, compasses, gyroscopes, motion detectors and sensors for orientation, measuring magnetic fields and capturing reflected infra-red light (to turn off the screen when it detects the phone is close to the ear, saving battery power and preventing inadvertent touches). All of that can be used for missile guidance and communications, adds Mr Shapir. The guidance and remote-control systems sold with consumer drones offer additional capabilities…

Part of the problem is that anyone can buy not just sophisticated hardware but also a 3D printer to make basic weapon components, says Rear-Admiral Brian Brakke, deputy director of operations at the Pentagon’s Joint Improvised-Threat Defeat Agency. In Iraq and Syria, Islamic State has been working on dropping improvised bombs from remotely controlled model aircraft. These might carry bigger payloads than the small quadcopters widely sold as drones to hobbyists and commercial operators. The jihadist group has also begun developing remote-control systems for driverless vehicles to deliver huge improvised explosive devices without suicide-volunteers, Mr Brakke believes….

Recent developments in biotechnology have moved the boundaries as well. So-called “biohacking” groups have begun experimenting with homespun processes, much as early computer hackers did with information technology. The biohackers see DNA as a form of software that can be manipulated to design new biological processes and devices. Some of the amateur labs are still relatively crude, but nevertheless there is concern that they could be used to create killer bugs or provide training for bioterrorists. America’s FBI has been watching developments and even organising some biohacker gatherings. That may seem reckless, but the idea is to encourage responsible behaviour and self-policing rather than risk a crackdown that drives the movement underground.

Excerpts from  Improvised Weapons, Hell’s Kitchen, Economist,  May 21, at 2016