Why are Moscow’s air defenses struggling to stop drone attacks? And why are oil refineries so vulnerable to Ukrainian strikes?

On June 16 and 18, Ukrainian drones broke through defenses in southeastern Moscow and knocked out both primary oil distillation units at the Moscow oil refinery. During the second strike, several fuel storage tanks caught fire, and smoke from the blaze blanketed the surrounding residential neighborhoods. In carrying out the attack, Ukraine’s Armed Forces achieved several objectives at once: they continued their campaign of strikes against oil refineries; demonstrated their ability to penetrate Russia’s most powerful and layered air defense zone; and produced striking footage that they showed to Western allies. The footage was equally telling for Russian officials and military commanders: even in the Moscow region, the air defense system is plainly incapable of stopping a mass strike. Ukraine’s Armed Forces have learned to assemble the forces needed to overwhelm the radars and launch systems protecting the most heavily guarded facilities. Other defensive approaches are either used in limited ways or remain in the testing phase.