Rome and Kyiv have one thing in common – the distinctive whine of motor-scooter engines in the night. The difference is that in Kyiv the high, Vespa-like noise does not rise from the streets but drifts down from among snow-laden clouds. It’s the unmistakable sound made by Iranian-designed Shahed-136 suicide drones, essentially modern-day doodlebugs armed with warheads big enough to collapse a medium-sized building.