Our military wasn't defeated; it was the politicians who fucked it up by hamstringing the military and continuing to order them into position which couldn't be won.
Is there really any doubt that the Russian Army is poorly led, poorly trained and given poor equipment because Putin's Oligarchs are robbing the country blind?
Is there any doubt that the Russian Army is getting its ass kicked daily?
The US was in Vietnam for about a decade and lost over 56K men. The Russians have been in Ukraine for less than a year and have already lost over 20K men. Why else is Putin threatening nukes if he wasn't desperate about getting his ass kicked?
https://en.wikipedia.org/wiki/Casualties_of_the_Russo-Ukrainian_War#Total_casualties
Russian and allied forces
70,000–80,000 killed and wounded
(20,000 killed)