They are cheap, readily constructed from items lying around the garage and gardening shed, come in every imaginable shape and size and can be triggered in a myriad of ways. I am referring to improvised explosive devices or IEDs. This was the one tactical threat the U.S. didn’t plan for when it went into Iraq and Afghanistan and it nearly lost us the war. It cost the military and local civilians dearly in terms of lives, lost and individuals injured, often horribly. Responding to the IED threat also cost this country tens of billions of dollars to design and acquire fleets of specially-armored and protected vehicles, electronic jamming systems, advanced sensors and robots. The Pentagon stood up an entirely new command, the Joint IED Defeat Organization, just to combat this threat.
In the next insurgency, U.S. and coalition forces could find themselves facing a new equally dangerous and disruptive threat: unmanned aerial vehicles (UAVs), often called drones.
I am not referring to the large, high-flying, long-range and sophisticated unpiloted aerial vehicles such as the U.S. Reaper or Global Hawk or the Israel Heron. Rather, I am speaking of relatively small and very simple drones that would fly low, have limited range and carry a payload measured in pounds. In its recent conflicts, the U.S. military deployed several highly effective small UAVs that were built out of plastic parts, employed commercially available sensor systems and avionics and whose launch and recovery systems were constructed from parts available at Home Depot.
To date, there have been relatively few cases of other countries and, more important, non-state actors, employing drones. But they are coming. All the relevant technologies are proliferated around the world. The airframe can be made from cheap materials. They can be powered by battery-driven electric motors found in gardening implements. They need no better guidance system than the GPS that can be found in the average cell phone. But if you want command guidance you can get a small video camera almost anywhere and route the feed through that same cell phone connected to the local communications network. They can be built in a garage and launched from the driveway.
The proliferation of drones could radically alter the tactical battle space. For the first time, non-state adversaries would have an air force. Obviously, if they were equipped with cameras, drones could provide terrorists and insurgents with critical intelligence and targeting information. Loaded with even a few pounds of explosives, drones are precision-guided weapons able to be used against fixed and even mobile targets, something our adversaries lack in their current inventories of rockets and missiles. Deployed on ships, drones would provide our adversaries with a low-cost “aircraft carrier.”
Small drones pose three distinct challenges to advanced militaries different than either manned aircraft or missiles. The first is the engagement envelope. Because these drones are small, fly low and are very quiet, they would be difficult to detect and engage with existing air defense systems. There might be no warning of an attack. Missile defenses would be equally ineffective.
The second challenge drones pose is to the defenses’ magazines. Simply put, the defense is more likely to run out of interceptors before the insurgents run out of drones. If drones were employed in swarming attacks, the defense might not be able to shoot fast them down enough, even if it has the right number of interceptors, to stop the attack.
The third challenge, possibly the most difficult, is the cost-exchange ratio between cheap drones and relatively expensive defensive weapons. We have known for a long time that it was prohibitively expensive to buy enough conventional interceptor missiles to shoot down all incoming rockets and ballistic missiles. The key to the very successful Israeli Iron Dome defense is that it only engages those weapons that are heading for populated areas or infrastructure targets. An attack by drones employing advanced guidance systems would require the defense to intercept all the inbound UAVs. The cost-exchange ratio would be prohibitively expensive.
The U.S. military, in general, but the Army, in particular, needs to accept the reality that this threat is coming, and get in front of it. This means dealing with all three of the challenges posed by small, low flying drones. First, new sensors, probably airborne or on aerostats, are needed in order to allow existing systems such as the Navy’s Close in Weapons System or machine guns to be effective. Second, new weapons are needed in order to increase ammunition stocks and reverse the cost exchange ratio. This means tactical lasers or microwave weapons. The Army has a tactical laser demonstrator program that has demonstrated real effectiveness against drones. Finally, a combination of electronic warfare and passive defenses will be required to defeat the drones’ sensors and guidance systems.
Make no mistake, this threat is coming. The recent conflict in Gaza taught the world’s terrorists and insurgents about the limited utility of even massive arsenals of unguided rockets and missiles. They will be looking for an alternative weapon. All the components needed to build a small, precision-guided, weaponized drone are available at ISIS’s equivalent of Radio Shack.