CNN  —  On a Kyiv rooftop in late November, a small group of volunteers in mismatched fatigues keep anxious watch. By day, all are judges in Ukraine’s highest courts, but once a fortnight they come together as a makeshift air defense unit, armed only with a pair of Soviet-era machine guns to shoot down swarms of drones. It’s “the cheapest way,” said Yuriy Chumak, one of the volunteers and a serving Supreme Court justice, highlighting Ukraine’s reluctance to use expensive, Western-supplied