I don't follow this stuff very closely but I've come away with a few interesting data points and have come to the conclusion that Putin has no idea what he might be up against. In the past several weeks, the US has been literally carpet dumping state of the art anti-tank weapons and many tons of much more devastating weapons on Ukraine. Any sort of tank led invasion is going to be eviscerated. These are fire and forget weapons that in many cases are shoulder launched. One shot, one kill, guaranteed.
And let's not even talk about area denial weapons like bombs containing hundreds of shaped charge weapons that are programmed to pick their own targets. Then there are semi-autonomous drones that can carry multiple missiles. Cruise missiles, etc .
Beyond that, the air force has deployed their most advanced stealth fighters in Poland and the Baltic states. And who know WTF else.
Putin lives in the past and in an information bubble. He thinks this is still the old Soviet Union preparing for a German panzer column to roll into Moscow. That shit is as dead as the Maginot line.
With the doors of us military armories open wide like and expectant lover, thousands of tons of the most advanced, nefarious and hideously effective weapon are flowing out in a fucking deluge. Granted that there will be a lot of only marginally trained Ukrainians using them but they are much more motivated, clever and devious than Putin can possibly imagine. He's expecting a cake walk but he'll be walking into a red wedding.