I doubt tanks will roll anywhere, any attack will be from the air, and Ukraine can't stop that, they'll fold very quickly once it happens.
Boots on the ground are needed to hold dirt. It's possible that they could play it like the United States did at the beginning of the first Persian Gulf war - all airstrikes at the outset to soften them up for a bit, then move in with combined forces.
Cant imagine he would stop at the east, all that would create is another war of attrition further in, which is what he has now in Donbas.
I think he goes for Kiev, he will weant his own government in there as soon as possible. Odessa will be an immediete target also with its very large Russian population and almost no Ukrainians.
While I don't think that anything less than a full-scale invasion is likely, I'm suspicious. Success in warfare, at both the tactical and strategic levels, is often about doing something other than what the opponent expects. Putin has conceded strategic surprise in the event of full-scale invasion. That's either supreme arrogance (which is possible given the relative balance of forces) or indicates that he has something up his sleeve.
Simply seizing the breakaway republics and absolutely hammering anything along the existing battlefront has two potentially attractive benefits. First, it
ends the war of attrition while doing significant damage to Ukraine's armed forces. The only reason there's a war of attrition going on is that Russia has never fully entered the battlefield. Second, it solves the short-run political problem of "how do I get out of this situation with a political win while minimizing economic costs imposed by the West?"
Given what Putin said the other day and the publicly-released intelligence, I suspect that he'll launch the full-scale invasion and claim that it was the only way to put an end to the war of attrition. That said, he could have been deliberately leaking misinformation through our intelligence channels as cover for his actual objectives. The best way to seize the breakaway republics in an expeditious manner is to convince the opposition that a full-scale invasion is coming, so that they have to divide their forces to meet clear and present threats elsewhere, then hammer the spot he actually wants to seize.
Remember, this is a skilled former counterintelligence operative we're dealing with. Flipping the opposition's agents and using them to snooker the opposition is the gold standard in a counterintelligence operation.
