Assume, for purposes of argument, that Putin has decided the benefits of taking Ukraine exceed the costs. Given that the number of troops massed on the borders far exceeds what he needs for a minor campaign, and that taking another small slice of Ukraine doesn’t really change his position much, I have to believe that his objective would be to control the entire country. What would the invasion look like?
As with the American invasion of Iraq, it will start with a shock-and-awe demonstration designed to crush the will of the Ukrainians to resist, as well as to impress the rest of the world (and his domestic audience) with his virility. It will probably work. The problem, however, is that the Iraq analogy extends to the period after the “victory;” the ensuing occupation will require a huge number of Russian troops, and a large element of the Ukrainian population will fight back. There will also be numerous terrorist attacks on Russian soil, and plenty of Russian civilians will be killed. Support for the war, always questionable, will plunge, as both sides descend into barbarism, and Ukraine becomes a much larger version of Chechnya.
Iraq was a ghastly mistake, as I predicted from the beginning. Ukraine would be, too.