Yes, it’s already time to be worried — very worried. As the wars in Ukraine and Gaza have shown, the earliest drone equivalents of “killer robots” have made it onto the battlefield and proved to be devastating weapons. But at least they remain largely under human control. Imagine, for a moment, a world of war in which those aerial drones (or their ground and sea equivalents) controlled us, rather than vice-versa. Then we would be on a destructively different planet in a fashion that might seem almost unimaginable today. Sadly, though, it’s anything but unimaginable, given the work on artificial intelligence (AI) and robot weaponry that the major powers have already begun. Now, let me take you into that arcane world and try to envision what the future of warfare might mean for the rest of us.
By combining AI with advanced robotics, the U.S. military and those of other advanced powers are already hard at work creating an array of self-guided “autonomous” weapons systems — combat drones that can employ lethal force independently of any human officers meant to command them. Called “killer robots” by critics, such devices include a variety of uncrewed or “unmanned” planes, tanks, ships, and submarines capable of autonomous operation. The U.S. Air Force, for example, is developing its “collaborative combat aircraft,” an unmanned aerial vehicle (UAV) intended to join piloted aircraft on high-risk missions. The Army is similarly testing a variety of autonomous unmanned ground vehicles (UGVs), while the Navy is experimenting with both unmanned surface vessels (USVs) and unmanned undersea vessels (UUVs, or drone submarines). China, Russia, Australia, and Israel are also working on such weaponry for the battlefields of the future.
The imminent appearance of those killing machines has generated concern and controversy globally, with some countries already seeking a total ban on them and others, including the U.S., planning to authorize their use only under human-supervised conditions. In Geneva, a group of states has even sought to prohibit the deployment and use of fully autonomous weapons, citing a 1980 U.N. treaty, the Convention on Certain Conventional Weapons, that aims to curb or outlaw non-nuclear munitions believed to be especially harmful to civilians. Meanwhile, in New York, the U.N. General Assembly held its first discussion of autonomous weapons last October and is planning a full-scale review of the topic this coming fall.
Some American strategists have championed an alternative approach to the use of autonomous weapons on future battlefields in which they would serve not as junior colleagues in human-led teams but as coequal members of self-directed robot swarms.
For the most part, debate over the battlefield use of such devices hinges on whether they will be empowered to take human lives without human oversight. Many religious and civil society organizations argue that such systems will be unable to distinguish between combatants and civilians on the battlefield and so should be banned in order to protect noncombatants from death or injury, as is required by international humanitarian law. American officials, on the other hand, contend that such weaponry can be designed to operate perfectly well within legal constraints.
However, neither side in this debate has addressed the most potentially unnerving aspect of using them in battle: the likelihood that, sooner or later, they’ll be able to communicate with each other without human intervention and, being “intelligent,” will be able to come up with their own unscripted tactics for defeating an enemy — or something else entirely. Such computer-driven groupthink, labeled “emergent behavior” by computer scientists, opens up a host of dangers not yet being considered by officials in Geneva, Washington, or at the U.N.
For the time being, most of the autonomous weaponry being developed by the American military will be unmanned (or, as they sometimes say, “uninhabited”) versions of existing combat platforms and will be designed to operate in conjunction with their crewed counterparts. While they might also have some capacity to communicate with each other, they’ll be part of a “networked” combat team whose mission will be dictated and overseen by human commanders. The Collaborative Combat Aircraft, for instance, is expected to serve as a “loyal wingman” for the manned F-35 stealth fighter, while conducting high-risk missions in contested airspace. The Army and Navy have largely followed a similar trajectory in their approach to the development of autonomous weaponry.
The Appeal of Robot “Swarms”
However, some American strategists have championed an alternative approach to the use of autonomous weapons on future battlefields in which they would serve not as junior colleagues in human-led teams but as coequal members of self-directed robot swarms. Such formations would consist of scores or even hundreds of AI-enabled UAVs, USVs, or UGVs — all able to communicate with one another, share data on changing battlefield conditions, and collectively alter their combat tactics as the group-mind deems necessary.
“Emerging robotic technologies will allow tomorrow’s forces to fight as a swarm, with greater mass, coordination, intelligence and speed than today’s networked forces,” predicted Paul Scharre, an early enthusiast of the concept, in a 2014 report for the Center for a New American Security (CNAS). “Networked, cooperative autonomous systems,” he wrote then, “will be capable of true swarming — cooperative behavior among distributed elements that gives rise to a coherent, intelligent whole.”
As Scharre made clear in his prophetic report, any full realization of the swarm concept would require the development of advanced algorithms that would enable autonomous combat systems to communicate with each other and “vote” on preferred modes of attack. This, he noted, would involve creating software capable of mimicking ants, bees, wolves, and other creatures that exhibit “swarm” behavior in nature. As Scharre put it, “Just like wolves in a pack present their enemy with an ever-shifting blur of threats from all directions, uninhabited vehicles that can coordinate maneuver and attack could be significantly more effective than uncoordinated systems operating en masse.”
In 2014, however, the technology needed to make such machine behavior possible was still in its infancy. To address that critical deficiency, the Department of Defense proceeded to fund research in the AI and robotics field, even as it also acquired such technology from private firms like Google and Microsoft. A key figure in that drive was Robert Work, a former colleague of Paul Scharre’s at CNAS and an early enthusiast of swarm warfare. Work served from 2014 to 2017 as deputy secretary of defense, a position that enabled him to steer ever-increasing sums of money to the development of high-tech weaponry, especially unmanned and autonomous systems.
From Mosaic to Replicator
Much of this effort was delegated to the Defense Advanced Research Projects Agency (DARPA), the Pentagon’s in-house high-tech research organization. As part of a drive to develop AI for such collaborative swarm operations, DARPA initiated its “Mosaic” program, a series of projects intended to perfect the algorithms and other technologies needed to coordinate the activities of manned and unmanned combat systems in future high-intensity combat with Russia and/or China.
“Applying the great flexibility of the mosaic concept to warfare,” explained Dan Patt, deputy director of DARPA’s Strategic Technology Office, “lower-cost, less complex systems may be linked together in a vast number of ways to create........