In a field in Germany this spring, a column of M1A2 tanks and Bradley infantry fighting vehicles moved forward — and was systematically destroyed before it could achieve anything. The attackers were not a rival superpower's army. They were a small team of Ukrainian drone operators, participating in Combined Resolve, a semiannual US military exercise held from 9 April to 10 May. The American troops on the receiving end, drawn from the 3rd Armored Brigade Combat Team of the 1st Cavalry Division and normally based at Fort Hood, Texas, were given something real soldiers in Ukraine are not: the ability to respawn.

That detail — borrowed from video-game culture — captures the jarring gap between the exercise and the war it was designed to study. Ukrainian operators mimicked tactics refined in actual combat: dropping simulated bombs from altitude or guiding drones close enough to replicate a kamikaze strike. Armoured vehicles that cost tens of millions of dollars were being neutralised so rapidly that US commanders were forced to reset scenarios repeatedly in order to give their troops enough training repetitions. By the end of the two-week exercise, American soldiers had learned to disperse their formations, seek concealment more aggressively, and deploy electronic-warfare countermeasures — lessons that Ukrainian fighters had paid for in blood.

The exercise was not an isolated revelation. In May, Ukrainian drone teams also participated in Aurora 26, a Swedish-led NATO exercise, where they destroyed dozens of armoured vehicles during a mock mechanised assault and eventually forced planners to reset that war game as well.