Russia can’t even capture the whole of Ukraine. How long have the 2 been fighting? Our support has kept Russia at bay.
We can’t even capture and control all of Afghanistan. What’s your point?
I’d also note that the Ukraine was actually where the Soviet Union made most of their post war tanks - the Ukraine is reasonably well armed and trained, and the outside aid they’re getting certainly helps. On the other hand, the Russians aren’t really pushing into it with everything they have and are also fighting in Syria.