Russia is no match for the United States on the battlefield, and not even close to matching all of NATO.
That is very true. It was also true that Darren Wilson was no match for Michael Brown, but Darren Wilson had a .40 caliber pistol and the will to use it, and Michael Brown is dead. As the Old West maxim explained, "God made big men and little men, but Sam Colt made 'em equal."
Limited wars are fought on neutral ground where neither side faces annihilation, while wars fought on home turf are existential and therefore total. During the Cold War the borderlands were aligned with the Warsaw Pact, and we were fully prepared to use nuclear weapons to save Western Europe from annihilation. Now the borderlands between Western Europe and Russia have been absorbed by NATO, so the risk of war has become existential to Russia. As a result, it is reckless to believe that a major war on Russia's border will not involve nuclear weapons.
Those who underestimate Russia have probably not been to the East Front, not studied it. They’re likely raised on modern USA is unbeatable, Normandy and Pacific WWII. I am patriotic, but not naive. USA is mostly illusion, and that illusion is not from the spirit of YHVH. Be prepared to be surprised:
Psalm 127:1
Unless the Lord builds the house, They labor in vain who build it;
Unless the Lord guards the city, The watchman keeps awake in vain.