L ast month, on my way home from Kyiv, I passed through Germany to visit one of the world’s largest weapons manufacturers. My hope was to see its response to the rise of drone warfare. The company, Rheinmetall, is best known for making artillery and tanks; the Ukrainians have fought the Russian army to a virtual standstill by learning how to destroy such old-school armaments with cheaply made drones. I thought I would find the leaders of Rheinmetall seized by the threat of this revolution in