Today, Russian missile assaults are intensifying, not receding. In March, Russia hit Ukraine with 264 missiles and 515 drones. A relentless bombardment of Kharkiv is making Ukraine’s second city uninhabitable.

In response, Kyiv’s most successful strategy to date has been its ingenious use of Ukrainian-made long-range drones to strike oil refineries, gas liquefaction plants, military airfields, arms factories and gas storage facilities deep inside Russia. These daily attacks are growing bolder and more sophisticated, from a musical drone that blared German music — Apocalypse Now-style — as it honed in on its target, to a converted pilot-less Cessna plane backed with explosives that struck a Shahed drone factory in Tatarstan, 750 miles from Ukraine.

The Washington-based Institute for the Study of War has said that the attacks represent “a significant inflection in Ukraine’s demonstrated capability to conduct long-range strikes far into the Russian rear.” And the strategy is hurting Russia: fifteen of its thirty oil refineries have been struck since January, knocking out 10 to 14 percent of the refinery capacity, driving prices up at the pumps and prompting the Kremlin to impose restrictions on gasoline exports from March to September.