Putin claims that Ukraine has no ‘antidote’ to Russia’s new jet-powered drones. Kyiv has already shown it can shoot them down, but doing it at scale could cost billions.

Speaking to reporters on the sidelines of the Cultural Forum, Vladimir Putin said Ukraine was seeking an “air ceasefire” out of weakness — especially because it feared Russia’s new jet-powered drones. The Russian president believes Kyiv has no “antidote” to these weapons. They are dangerous, but they lack the chief advantage of the earlier “Geran” drones: low cost. Developing defenses against the faster drones will also be expensive for Ukraine. Here is how the latest turn in the technological a...