Russia is planning to exhaust Ukraine

Afraid to fan the flames of dissent in an unpopular war by sending in more troops, Russia has been accused of launching waves of so-called "kamikaze" drones against Ukrainian cities and power stations in recent months. Ukraine's government and Western intelligence agencies say Russia has been using Iranian-made Shahed-136 drones in the conflict since autumn last year. Also called the Geranium-2 by Russia, it has explosives in a warhead on its nose and is designed to loiter over a target until it is instructed to attack.

https://www.bbc.com/news/world-62225830