war on the rocks

Robots at War and the Quality of Quantity

February 26, 2015

Editor’s note: This is the second article in a six-part series, The Coming Swarm, on military robotics and automation as a part of the joint War on the Rocks-Center for a New American Security Beyond Offset Initiative. Read the first entry in the series, “Between a Roomba and a Terminator.”


The U.S. Department of Defense has launched the search for a “third offset strategy,” an approach to sustain U.S. military technological superiority against potential adversaries. But, for a number of reasons, this strategy is different than the previous two. Even the name “offset” may not be valid. The first two strategies were aimed at “offsetting” the Soviet numerical advantage in conventional weapons in Europe, first with U.S. nuclear weapons and later with information-enabled precision-strike weapons. But this time around, it may be the United States bringing numbers to the fight.

Uninhabited and autonomous systems have the potential to reverse the multi-decade trend in rising platform costs and shrinking quantities, allowing the U.S. military to field large numbers of assets at affordable cost. The result could be that instead of “offsetting” a quantitative advantage that an adversary is presumed to start with, the United States could be showing up with better technology and greater numbers.

The value of mass

The United States out-produced its enemies in World War II. By 1944, the United States and its Allies were producing over 51,000 tanks a year to Germany’s 17,800 and over 167,000 planes a year to the combined Axis total of just under 68,000. Even though many of Germany’s tanks and aircraft were of superior quality to those of the Allies, they were unable to compensate for the unstoppable onslaught of Allied iron. Paul Kennedy writes in The Rise and Fall of Great Powers:

…by 1943-1944 the United States alone was producing one ship a day and one aircraft every five minutes! … No matter how cleverly the Wehrmacht mounted its tactical counterattacks on both the western and eastern fronts until almost the last months of the war, it was to be ultimately overwhelmed by the sheer mass of Allied firepower.

The Cold War saw a shift in strategy, with the United States instead initially relying on nuclear weapons to counter the growing Soviet conventional arsenal in Europe, the first “offset strategy.” By the 1970s, the Soviets had achieved a three-to-one overmatch against NATO in conventional forces and a rough parity in strategic nuclear forces. In response to this challenge, the U.S. military adopted the second offset strategy to counter Soviet numerical advantages with qualitatively superior U.S. weapons: stealth, advanced sensors, command and control networks, and precision-guided weapons.

The full effect of these weapons was seen in 1991, when the United States took on Saddam Hussein’s Soviet-equipped army. Casualty ratios in the Gulf War ran an extremely lopsided 30-to-1. Iraqi forces were so helpless against American precision airpower that the White House eventually terminated the war earlier than planned because media images of the so-called “highway of death” made American forces seem as if they were “cruelly and unusually punishing our already whipped foes,” in the words of Gulf War air commander General Chuck Horner. Precision-guided weapons, coupled with sensors to find targets and networks to connect sensors and shooters, allowed the information-enabled U.S. military to crush Iraqi forces fighting with unguided munitions.

What happens when they have precision-guided weapons too?

The proliferation of precision-guided weapons to other adversaries is shifting the scales, however, bringing mass once again back into the equation. The United States military can expect to face threats from adversary precision-guided munitions in future fights. At the same time, ever-rising platform costs are pushing U.S. quantities lower and lower, presenting adversaries with fewer targets on which to concentrate their missiles. U.S. platforms may be qualitatively superior, but they are not invulnerable. Salvos of enemy missiles threaten to overwhelm the defenses of U.S. ships and air bases. Even if missile defenses can, in principle, intercept incoming missiles, the cost-exchange ratio of attacking missiles to defending interceptors favors the attacker, meaning U.S. adversaries need only purchase more missiles to saturate U.S. defenses.

Enter the swarm

Uninhabited systems offer an alternative model, with the potential to disaggregate expensive multi-mission systems into a larger number of smaller, lower cost distributed platforms. Because they can take greater risk and therefore be made low-cost and attritable – or willing to accept some attrition – uninhabited systems can be built in large numbers. Combined with mission-level autonomy and multi-vehicle control, large numbers of low-cost attritable robotics can be controlled en masse by a relatively small number of human controllers.

Large numbers of uninhabited vehicles have several potential advantages:

  • Combat power can be dispersed, giving the enemy more targets, forcing the adversary to expend more munitions.
  • Platform survivability is replaced with a concept of swarm resiliency. Individual platforms need not be survivable if there are sufficient numbers of them such that the whole is resilient against attack.
  • Mass allows the graceful degradation of combat power as individual platforms are attrited, as opposed to a sharp loss in combat power if a single, more exquisite platform is lost.
  • Offensive salvos can saturate enemy defenses. Most defenses can only handle so many threats at one time. Missile batteries can be exhausted. Guns can only shoot in one direction at a time. Even low cost-per-shot continuous or near-continuous fire weapons like high energy lasers can only engage one target at a time and generally require several seconds of engagement to defeat a target. Salvos of guided munitions or uninhabited vehicles can overwhelm enemy defenses such that “leakers” get through, taking out the target.

These advantages could translate to new, innovative approaches for using uninhabited systems, just a few of which are explored below.

The miniature air-launched decoy (MALD) and miniature air-launched decoy – jammer (MALD-J) – loitering air vehicles that are not quite munitions and are not aircraft – hint at the potential of small, loitering uninhabited air vehicles and air-mobile robots. The MALD functions as an aerial decoy to deceive enemy radars, while the MALD-J jams enemy radars. Similar future uninhabited air vehicles, launched from aircraft, ships or submarines, could saturate enemy territory with overwhelming numbers of low-cost, expendable systems. Like D-Day’s “little groups of paratroopers” dropped behind enemy lines, they could sow confusion and wreak havoc on an enemy.

Loitering electronic attack weapons could create an electronic storm of jamming, decoys and high-powered microwaves. Small air vehicles could autonomously fly down roads searching for mobile missiles and, once found, relay their coordinates back to human controllers for attack.

Such aircraft would be small and would require a means of getting to the fight. This could include submarines parked off an enemy’s coast, uninhabited missile boats that race to the enemy’s coastline before launching their payloads into the air, large bomber or cargo aircraft, or even uninhabited undersea pods like DARPA’s Hydra program.

A similar approach could help the Army expand combat power on land. The Army has thousands of fully functional ground vehicles such as HMMWVs and M113 armored personnel carriers that will not be used in future conflicts because they lack sufficient armor to protect human occupants. At very low cost, however, on the order of tens of thousands of dollars apiece, these vehicles could be converted into robotic systems. With no human on board, their lack of heavy armor would not be a problem.

This could be done at low cost using robotic appliqué kits – sensors and command systems that are applied to existing vehicles to convert them for remote or autonomous operation. Robotic appliqué kits have already been used to convert construction vehicles into remotely operated Bobcats and bulldozers to counter improvised explosive devices.

Applied to existing vehicles, robotic appliqué kits could give the Army a massive robot ground force at extremely low cost. The sheer mass of such a force, and the ability to apply it in sacrificial or suicidal missions, could change how the Army approaches maneuver warfare.

Uninhabited ground vehicles could be the vanguard of an advance, allowing robots to be the “contact” part of a “movement to contact.” Robotic vehicles could be used to flush out the enemy, flank or surround them, or launch feinting maneuvers. Uninhabited vehicles could be air-dropped behind enemy lines on suicide missions. Scouting for targets, they could be used by human controllers for direct engagements or could send back coordinates for indirect fire or aerial attacks.

These are just some of the possibilities that greater mass could bring in terms of imposing costs on adversaries and unlocking new concepts of operation. Experimentation is needed, both in simulations and in realistic real-world environments, to better understand how warfighters would employ large numbers of low-cost expendable robotic systems.

And there would be other issues to work out. Robotic systems would still require maintenance, although mitigation measures could minimize the burden. Modular design would allow easy replacements when parts broke, allowing maintainers to cannibalize other systems for spare parts. And uninhabited systems could be kept “in a box” during peacetime with only a limited number used for training, much like missiles. For some applications where uninhabited systems would be needed in wartime but not in peacetime, mixed-component units that leverage National Guard and Reserve maintainers may be a cost-effective way to manage personnel.

A new paradigm for assessing qualitative advantage

The point of building large numbers of lower cost systems is not to field forces on the battlefield that are qualitatively inferior to the enemy. Rather, it is to change the notion of qualitative superiority from an attribute of the platform to an attribute of the swarm. The swarm, as a whole, should be more capable than an adversary’s military forces. That is, after all, the purpose of combat: to defeat the enemy. What uninhabited systems enable, is a disaggregation of that combat capability into larger numbers of less exquisite systems which, individually, may be less capable but in aggregate are superior to the enemy’s forces.

Disaggregating combat power will not be possible in all cases, and large (and expensive) vehicles will still be needed for many purposes. Expensive, exquisite systems will inevitably be purchased in small numbers, however, and so where possible they should be supplemented by larger numbers of lower-cost systems in a high-low mix. Neither a cheap-and-numerous nor an expensive-and-few approach will work in every instance, and U.S. forces will need to field a mix of high and low-cost assets to bring the right capabilities to bear – and in the right numbers – in future conflicts.


Paul Scharre is a fellow and Director of the 20YY Warfare Initiative at the Center for a New American Security (CNAS) and author of CNAS’ recent report, “Robotics on the Battlefield Part II: The Coming Swarm.” He is a former infantryman in the 75th Ranger Regiment and has served multiple tours in Iraq and Afghanistan.


Photo credit: asuscreative