Ukrainian drone operators can instantly map a safe route to the target using this system, which was developed for them by the U.S. software company Palantir. To demonstrate it for me, a Palantir engineer pressed a key: The simulated drone headed south, turned east in a wide semicircle to avoid one air-defense zone, carved a semicircle west around another, zigzagged a route through the jammers — and finally hit the target.

This software-driven attack system is part of an astonishing wave of innovation driven by the Ukraine conflict. Fifteen months ago, I described the automated intelligence and targeting systems of “the algorithm war,” as technologists here described it. We’re now at version 2.0 — or maybe it’s 4.0. The race for advantage keeps accelerating. Russia, after a slow start, is proving nearly as adept at innovation as Ukraine.

“The nature of warfare has changed,” explains Giorgi Tskhakaia, a defense adviser to the Ukrainian Ministry of Digital Transformation. “It’s a technology war. If you don’t know the path to evade air defense and EW (electronic warfare), you will lose most or all of your drones. It’s a cat-and-mouse game. We are learning, and the oppressor is learning, as well.”

President Volodymyr Zelensky has pledged that Ukraine will build 1 million drones this year to supplement its dwindling supply of weapons and artillery from the West. On any given day, each side has nearly 3,000 drones in the air, Tskhakaia says. The front line has become a digital shooting gallery.

Ukrainian officials tell me that electronic jammers are everywhere at the front, blocking GPS and other signals. But some drones get through. Gruesome videos showing them pursuing desperate soldiers until they connect in a white burst of light look like military versions of a snuff film.

I traveled here with a team from Palantir that’s advising the Ukrainian government on software tools for this constantly evolving battlespace. “The question is how fast you can adapt,” explained the Palantir engineer who’s coordinating the company’s operations here. Technology cycles evolve every few months, with each countermeasure producing an offsetting response.

This revolution in combat is powered by an extraordinary tech ecosystem. Over the past 18 months, the number of Ukrainian drone companies has grown from seven to nearly 300, says Tskhakaia. These local enterprises are aided by high-tech entrepreneurs from around the world who have banded together in a modern version of the idealistic “international brigade” that fought with Spanish Republicans against the fascists in the Spanish Civil War.

This tech cadre is one of the most fascinating and least understood aspects of the war. In addition to some big companies like Palantir and Microsoft, Ukraine’s tech supporters include several prominent American billionaires, an array of U.S. start-ups and entrepreneurs from across Europe to North America and Australia. It’s a weird fusion of Silicon Valley and trench warfare.

Ukrainian technology has evolved from simple quadcopters that can travel a few miles to big fixed-wing drones that can reach deep inside Russia. The next step is to equip these drones with virtual mapping and artificial intelligence so that they can get to their targets even through a blizzard of Russian jamming. A half-dozen companies here are already perfecting that AI technology — and making it cheap enough to power thousands of smart drones.

But as these autonomous systems evolve, the danger of escalation — and proliferation around the globe — is huge.

Human Rights Watch is one of many activist groups warning about what it calls “digital dehumanization” in warfare. “New law is needed on autonomy in weapons systems to create boundaries between what is acceptable and unacceptable,” argues a coalition seeking to curb autonomous weapons like those Ukraine and Russia — and dozens of other countries — are deploying.

Using these new technologies, Ukraine is bringing the war home to Russia. The Ukrainians launch drones in waves, hoping that some will reach their targets. On March 12, for example, Russia said that Ukraine attacked with 25 drones, including one targeting Nizhny Novgorod, about 200 miles east of Moscow. On March 17, Ukraine sent 35 drones across the border, with one causing a fire at a refinery in Krasnodar.

The attacks on Russian refineries have been especially aggressive. Ukrainian intelligence officials told Reuters on March 17 that they had hit 12 Russian refineries. The news agency calculated this week that such attacks have shut about 14 percent of Russia’s refining capacity, including a strike this week on Russia’s third-largest refinery in Tatarstan.

Zelensky told me last week at his presidential compound that Ukraine needed to fight back against Russia’s attempt to destroy its energy grid, even though the reaction of U.S. officials “was not positive.”

“Why can’t we answer them?” Zelensky said. “Their society has to learn to live without petrol, without diesel, without electricity. … It’s fair.” Russia has launched more than 4,630 Iranian-designed Shahed drones against Ukraine, according to Kyiv’s calculations.

Francisco Serra-Martins, the chief executive of a start-up drone-maker called Terminal Autonomy, told me he’s now producing an “AQ 400 Scythe” drone that can fly nearly 500 miles. The company is also working on a version that will travel 1,200 miles. An émigré with roots in Australia and Portugal, he’s an example of Ukraine’s international high-tech ecosystem.

Serra-Martins’s products are described on the company’s website. He began with a simple quadcopter called “Scalpel” with a range of about six miles and a five-pound payload. He realized he could build cheap, wooden fixed-wing drones — the AQ 100 Bayonet that can carry seven pounds of explosives about 30 miles and the longer-range Scythe that can carry a nearly 100-pound payload.

Each month, Terminal Autonomy is now building 3,000 Bayonets and 100 Scythes, which Serra-Martins says he could ramp up to 500 or more. In competition with other start-ups, Serra-Martins says he’s learning to cut costs. He builds the drones with cheap wood in converted furniture factories. He hopes to slash the price of a Bayonet drone from about $2,000 to $1,000 later this year.

“That’s the key to winning this war,” he says — low-cost, expendable but potent drones. His company’s slogan: “Strategic warfare, democratized.”

The start-up defense culture is spreading. UkrJet produces a Czech-designed long-range drone called the Beaver. DEF-C, founded in 2015, is now making long-range attack drones, too. A nonprofit called Escadrone is producing cheap “first-person view” drones for less than $500. A company based in Saskatchewan is selling Ukraine software and AI systems that can guide the drones.

“Our motto is, ‘The drones are fighting, not the people,’” says Tskhakaia. He thinks autonomous weapons will save precious lives, Ukraine’s scarcest resource. The country’s roughly 20,000 drone operators can work away from the front lines, often in protected underground bunkers, he notes.

The long congressional delay in approving military assistance for Kyiv has had an unlikely upside. Countries starving for weapons, like Ukraine, learn to innovate and make their own.