The Soviet Union had twice as many people as Russia today. And they coundn't beat a bunch of cavemen in Afghanistan (similar population as Ukraine btw).
They are both pretty even technologically but Ukraine has what, about one tenth the population.
More like 1/4 (at the beginning of the war).
The Afghans bested the Soviets because we funded, armed and fully supported the Mujahedeen the whole way through.
Dan Rather was confident enough to be embedded with them in the field.
We die laughing about it now, but it was what it was, and the CIA was hitting on all cylinders.