Interoperability would address a major problem of European armed forces: fragmented command-and-control systems that cannot easily share data. Much commentary attributes Ukrainian battlefield progress in 2026 to certain drone models, underestimating the significance of Delta, Ukraine’s command-and-control system. Different countries, and in many cases different service branches within the same country, operate different command-and-control systems, with limited interoperability. Without integrated digital architecture and interoperability, a pan-European combat cloud and AI-assisted command-and-control system cannot work. But AI-powered command-and-control systems will be the backbone of modern warfare, the defining factor in a military’s ability to fight effectively.