On a single winter morning in February 2022, the skies over Ukraine went dark. Flight trackers that normally displayed hundreds of aircraft across Kyiv, Dnipro, Odesa, and Lviv suddenly emptied. Pilots received diversion instructions mid-air. Dispatchers began redrawing routes that had been stable for decades. Air traffic controllers across Europe watched one of the continent’s most important east-west corridors disappear from the map in minutes. Airports that once processed