Make no mistake, the day the US decides that Adolf Putin looses in Donbas, the young soldiers in there will die and Putin will loose. That may or may not happen, it can be sooner, later or even never. I would not like to be one of the guys that finds out the hard way.
Thank you for worrying about the fate of Russian soldiers, so far everything seems to be fine. A month after the surrender of Azov's militants in Mariupol, it can be said that the Eastern Front has crumbled. Ukraine is losing the battle in the Donbass, and so far no military assistance from the West has been able to change this.