Mearsheimer's getting a lot of airplay right now, but his analysis is straight out of the 19th century "great game" -- Ukraine is hardly even mentioned. His reasoning is all about the territorial conflicts of the "great powers".

In reality Russia is a small, poor, and mostly irrelevant state, mainly getting airtime because it has nukes. Without the nukes it would be taken as seriously as other countries of its economic clout, like Australia. Which is to say, not taken seriously at all.