In laymen’s terms, “kill boxes” sound like torture devices. In military jargon, they are almost incomprehensible; as defined in the Department of Defense Dictionary, they are “a three-dimensional area reference that enables timely, effective coordination and control and facilitates rapid attacks.” But despite their ominous name and complicated technical definition, kill boxes are actually relatively simple in concept: They are three-dimensional cubes of space on a battlefield in which members and allies of the United States military are completely free to open fire.

According to the DoD, “there is no formal kill-box doctrine or tactics, techniques or procedures.” They require a sophisticated web of logistical, bureaucratic, and technological expertise to implement. Like most military tactics, kill boxes aren’t new—they’ve been around for nearly 30 years now. But they are constantly being reinvented for new conflicts. In recent years, kill-box strategy has shifted: They are now used in conflicts that are not between two states, but rather within states against terrorists and fighters who aren’t members of any particular country’s military. With this change, two things have started happening. First, kill boxes have materialized in places the local population might not expect. And second, kill boxes have been used in conjunction with disposition matrices, or “kill lists.” The DoD uses these to target people whose “pattern of life” fit the parameters of an algorithm, rather than specific individuals. For example: Say someone who owns a cellphone has been calling numbers that trigger a response from a computer at the Pentagon. Analysts will triangulate the cellphone’s whereabouts, and military leaders might initiate a “kill box” at that location, authorizing soldiers to kill everyone within the “box.” Mission accomplished.

The use of kill boxes has mutated into something almost unrecognizable from the tactic’s origins at the end of the Cold War, let alone older forms of warfare. To effectively use the tactic, a military must have profound technological and logistical advantages over its enemy. Success depends on access to a web of satellites, high-tech communications equipment, pilots, and ground crews trained well enough to execute nearly constant defensive attacks. It requires more planning and specialization than, say, the kind of air war that America fought in World War II, which involved pitched battles in which specific objectives were targeted as the opportunity arose.

On January 30, 1991, during Operation Desert Storm, kill boxes were put into practice for the first time. And they worked. Destroying the Saddam Hussein’s air and ground forces was simple. Stationary kill boxes—quadrants roughly 350 cubic miles in size—were designated within specific coordinates, which military forces would patrol at regular intervals. During the Gulf War, “A single quadrant comprised an area almost equaling the size of New York City,” writes Richard Davis in Decisive Force: Strategic Bombing in the Gulf War. “These devastating and ubiquitous operations accomplished both the aerial interdiction of Iraqi supply and the destruction of Iraqi military equipment and personnel.” The Iraqi First and Third Mechanized Divisions were decimated before they even had the chance to put together a defense. Kill boxes might have been one strategic reason why the Gulf War only lasted 100 hours.

In particular, kill boxes proved an efficient way for the Air Force to dismantle opposing militaries. This worked in 1991, and again during the first years of the wars in Iraq and Afghanistan. In these early stages, using a kill box required positive identification of an enemy target, a process called PID, before engaging. “We have to visually identify the target and we have to determine whether it’s a hostile [military] target. We determine that it’s not friendly by using visual recognition features and through ground elements of the nearest friendly positions,” Air Force Major Greg Defore told National Defense Magazine in 2003. In other words: Servicemen look at who or what they’re going to shoot with their own eyes before shooting to make sure the person or object is actually the part of the enemy’s military forces. “You may be 100 percent sure that a vehicle is not a friendly and still not engage. It could, for instance, be a humanitarian food truck or a farm vehicle,” Defore said.

This strategy worked well during the initial invasion of Iraq, but only because the opposing team was wearing a jersey, so to speak. It was possible to look at a truck and know whether or not it was hostile. But as a conventional war degenerated into a complex quagmire of militants engaged in guerilla warfare, that sort of certainty wasn’t possible any longer. As Major James MacGregor explains in his paper, “Bringing the Box into Doctrine: Joint Doctrine and the Kill Box,” an officer from 1918 would have, with a little help, been able to understand the maps of the Gulf War: Enemy forces are here, friendly forces over here, that sort of thing. But today, the enemy could be anyone, anywhere. This type of warfare doesn’t naturally lend itself well to kill boxes. As the American military started using kill boxes in conjunction with drones in targeted killings, it effectively grafted a strategy from the past onto the present, a la Frankenstein. The military began using kill boxes in the so-called war on terror as a technique to exert force in “ungoverned spaces,” territories that are not controlled by a state and are populated by people who might not share American cultural values. Kill boxes are only used in places that are very different from the United States; military forces would never initiate a kill box Manchester or Ann Arbor, for example, even if a suspected terrorist lived there. Too many innocent people would be killed. The innocent people living in Afghanistan or Yemen, however, are apparently judged by a different standard. And this is the moral cost of the kill box: When used widely and indiscriminately, the tactic devalues human life.

Western militaries have an ignoble history of using abstract battlefield metaphors to justify killing people. According to Nicholas Blomley, a professor at Simon Fraser University in Vancouver, European militaries in colonial territories saw maps as “‘metaphors for both the process of scientific research and the ideal of the ordered state of nature,’” In other words, they wanted to reduce the land where many people lived down to the simplicity and order of a map, which represented both a cultural ideal and a military goal. Its very existence represented a kind of control over the territory. Relying on kill boxes, together with other high-tech tools of warfare such as drones, is just the newest and most sophisticated way in which Western military powers mistake a strategic tool for a literal description of reality. When a kill box is implemented and the people or objects within it are destroyed, terrorists are not necessarily killed, just as innocent people are not necessarily spared. Sometimes, simply finding yourself inside of an American kill box is enough to be retroactively defined as guilty. If a DoD algorithm identifies a person as a combatant, the military assumes he’s a combatant; the abstract proof is considered sufficient. It’s the very definition of confusing the map for the territory it represents.

In a 2010 letter to President Obama, Human Rights Watch wrote, “The notion that the entire world is automatically by extension a battleground in which the laws of war are applicable is contrary to international law. How does the administration define the ‘global battlefield’ … ? Does it view the battlefield as global in a literal sense, allowing lethal force to be used, in accordance with the laws of war, against a suspected terrorist in an apartment in Paris, a shopping mall in London, or a bus station in Iowa City?” The French therorist Grégoire Chamayou has compared the new use of kill boxes to target individuals or small groups, rather than enemy militaries, to the difference between hunting and combat. “While warfare is defined … by combat, hunting is essentially defined by pursuit. Two distinct types of geography correspond to the two activities,” he writes. “Combat bursts out wherever opposing forces clash. Hunting, on the other hand, takes place wherever the prey goes. As a hunter-state sees it, armed violence is no longer defined within the boundaries of a demarcated zone but simply by the presence of an enemy-prey who, so to speak, carries with it its own little mobile zone of hostility.”

Kill boxes have freed American military pursuits from the limitations of time and space—and, importantly, strict scrutiny. As the blog Understanding Empire argues, “During the Clinton cabinet, officials worried and debated fiercely whether or not eliminating bin Laden was legal (and ethical), as Steve Coll’s Ghost Wars captures excellently. Now, targeted killing has become [so] routine that the Obama administration is seeking ways to codify and streamline it.” A strategy that works effectively during conventional warfare has been slowly repurposed and re-contextualized.

During his Nobel Peace Prize acceptance speech, Obama said, “War is justified only when certain conditions were met; if it is waged as a last resort or in self-defense; if the force used in proportional; and if, whenever possible, civilians are spared from violence.” The military’s current use of kill boxes in tandem with kill lists defies each of those criteria. These tools are now used in the pursuit of something that only superficially resembles war. In practice, these tactics have more in common with expensive and reckless high-tech hunting. They are unethical, and as terrorism and militancy proliferate in the regions where they are being implemented, they also appear to be ineffective.