Moscow barreled hundreds of drones toward four key regions in Ukraine overnight, just as lawmakers in Kyiv scrambled to approve additional defense spending against the backdrop of intensified Russian attacks over the past few days.

The relentless strikes rely on a drone that costs as little as $50,000 to make—about as a BMW M Sport costs in India. The cost to shoot one down? Often more than a million dollars. As James Black of the RAND Corporation put it,