Ukraine's fight shows how quickly drone tech becomes obsolete. Wolfgang Schwan/Anadolu via Getty Images Ukraine is showing NATO how critical drones are — and how fast the fight changes. Drones can quickly become outdated, complicating future war planning. A NATO official said drones can't be stockpiled like traditional hardware. NATO is racing to prepare for the next drone war, but officials warn that building millions of drones now could leave the alliance with stockpiles of outdated weapons