Although lessons about particular weapons systems are relevant, the more important lesson is about the ecosystem necessary for these new tools to be effective. Ukraine, for instance, has developed Sky Fortress, a network of 14,000 acoustic sensors that locate Russian drones by sound, even at altitudes radar cannot see, to provide a high-fidelity picture of incoming threats. It also has its own battle-management software systems that direct unmanned surveillance, as well as the Unmanned Services Force, an entirely new military service—alongside the army, navy, and air force—that is dedicated to drone warfare, with its own doctrine, leader development, procurement processes, and even recruiting and basic training. Perhaps most critically, the ecosystem in Ukraine also includes manufacturers that can produce enormous quantities of unmanned systems and constantly refine the software and hardware of those systems in response to developments on the battlefield.