But if the drawbacks of using artificially intelligent war machines are obvious, so are the advantages. Humans generally take about a quarter of a second to react to something we see—think of a batter deciding whether to swing at a baseball pitch. But now machines we’ve created have surpassed us, at least in processing speed. Earlier this year, for example, researchers at Nanyang Technological University, in Singapore, focused a computer network on a data set of 1.2 million images; the computer then tried to identify all the pictured objects in just 90 seconds, or 0.000075 seconds an image.

The outcome wasn’t perfect, or even close: At that incredible speed, the system identified objects correctly only 58 percent of the time, a rate that would be catastrophic on a battlefield. Nevertheless, the fact that machines can act, and react, much more quickly than we can is becoming more relevant as the pace of war speeds up. In the next decade, missiles will fly near the Earth at a mile per second, too fast for humans to make crucial defensive decisions on their own. Drones will attack in self-directed swarms, and specialized computers will assault one another at the speed of light. Humans might create the weapons and give them initial instructions, but after that, many military officials predict, they’ll only be in the way.

“The problem is that when you’re dealing [with war] at machine speed, at what point is the human an impediment?” Robert Work, who served as the Pentagon’s No. 2 official in both the Obama and Trump administrations, said in an interview. “There’s no way a human can keep up, so you’ve got to delegate to machines.”