Russia historically has never had a problem sacrificing millions of its own people, with few or no political repercussions. Stalin survived his many failures and only death removed him as Dictator of the Soviet Union. Moreover, as Ukraine's air defenses are nearly exhausted (they'll be gone by mid-May) and as the West still - stupidly -refuses to provide fighter jets, chances are Russian air assets will be increasingly used to good effect and the few MBTs and IFVs that have been sent will simply be slow-moving targets for Russian air-to-ground missiles. This may change the battlefield calculus entirely, and not at all to Ukraine's advantage.