When Russia first launched its full-scale invasion of Ukraine, the conflict drew comparisons to wars of the twentieth century. Tanks, armored personnel carriers, and artillery dominated the battlefield, and both sides’ infantry were dug into trenches. We witnessed this old-school style of war when we made our first visit to Ukraine in September 2022. Since then, we have made regular trips to Ukraine, affording us firsthand insight into a monumental transformation: the beginning of a new kind of warfare.

In summer 2023, the commander of Ukraine’s Third Assault Brigade’s Drone Unit, whom we’ll call Fil (not his real name), told us that a new weapon had begun to change the conflict: first-person-view drones. These small, cheap, maneuverable quadcopters transmit real-time footage to their operators and detonate kamikaze-style on their targets. That year, Ukraine flooded the field with thousands of them and Russia soon followed suit. Today, hundreds of thousands of these drones fill the Ukrainian skies.

What began as a war with drones has become a war of drones. Indeed, two years ago, a Ukrainian brigade’s strength was judged mostly by its inventory of Western-supplied tanks, armored personnel carriers, and artillery. Since 2023, however, drones have become the most important weapon on the battlefield. Because of their low cost, speed, and precision, drones have now largely supplanted traditional weaponry, including antitank missiles, mortars, tanks, and even artillery and aircraft. Today, a unit’s power and resilience are dictated by its number of skilled drone operators and its ability to deploy drones at scale. (One of us, Schmidt, has been a longtime investor in defense technology companies, and is currently an investor in companies supplying drones to Ukraine.)

This represents a profound shift in warfare, largely instigated by Ukraine to compensate for its shortfalls in conventional weapons and manpower. In the world’s first drone war, drones determine how battles are won and how soldiers die: Ukrainian drone strikes now account for 90 percent of destroyed Russian tanks and armored vehicles and 80 percent of Russian casualties. They have also made it possible for each side to attack far past the frontlines without having to gain air superiority over the battlefield. Ukraine, for example, hit Russian airbases 5,000 miles from Kyiv in June by smuggling drones across the border and launching them from the beds of trucks.

Russia, for its part, was originally slower to field drones in large numbers. But it has dramatically increased its production of first-person-view drones, as well as those used for strategic bombardment, such as the Iranian-designed Shahed. Today, Moscow matches Kyiv’s extraordinary rate of technological adaptation. It has developed equally capable models, such as the Orlan, which is used for surveillance, and the Lancet, which loiters over a target before exploding on impact.

Because Russia and Ukraine are constantly iterating on hardware, software, and tactics, the war changes at a breathtaking rate. The saturation of drone surveillance, for example, has made nearly all troop movement visible and therefore vulnerable, creating a transparent battlefield: anything that moves near the frontline is struck within a matter of minutes. Drone pilots have become prime targets, and with many traditional weapons rendered obsolete, drones are increasingly fighting other drones. Amid this cycle of innovation, the two sides are inching toward a new frontier: entirely automated warfare.

Surveillance and reconnaissance drones have become so ubiquitous that both Russian and Ukrainian forces scarcely move in the daylight. During a recent visit, we witnessed the motion of a single Russian van, five miles from the frontline, cause a sensation among drone operators, who then destroyed it. To avoid detection, movement near the frontline tends to take place during sunrise and sunset, when neither the daylight video cameras nor night-vision infrared cameras operate properly.

The fight for information advantage is always important in war, but even more so in this one, where it means the ability to form and maintain resilient drone-based sensor networks over the battlefield. If a unit is “blinded”—unable to maintain surveillance drones overhead—it becomes exceedingly vulnerable. For that reason, roughly 3,000 Ukrainian troops work around the clock to operate reconnaissance drones, mostly Chinese-made DJI Mavics, along the entire 750-mile frontline. Ukrainian brigade command centers display as many as 60 of these drone feeds around the clock.

This transparency means that the military maxim “what can be seen can be hit” is truer on today’s battlefield than at any point in history. It is nearly impossible for either side to mass and maneuver forces along the frontline, as troops are now easily spotted forming up for attack. The Russian army has historically relied on its ability to deliver impressive firepower through concentrated tube and rocket artillery fire, but these tactics are useless when any attempt to amass forces is identified within minutes.........

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