Mearsheimer "has" all the information; it just doesn't fit his preferred narrative ("The U.S needs to stop picking on Russia so they can team up together against China"), so he discards the parts get in the way of that narrative. Such as the long and deep history of Russia's colonial attitude toward Ukraine, for example.
As to a more realistic narrative -- it's a bit more nuanced than the formulation you suggest, but even so -- is pretty much obvious once we look at the things Putin and key people around him have been saying, along with the last 350 years of so of Russia's history vis-a-vis its neighbors and Belarus and Ukraine in particular.
The links in the short comment tree below (which answered essentially the same question from just a few weeks ago) might be useful here:
As to a more realistic narrative -- it's a bit more nuanced than the formulation you suggest, but even so -- is pretty much obvious once we look at the things Putin and key people around him have been saying, along with the last 350 years of so of Russia's history vis-a-vis its neighbors and Belarus and Ukraine in particular.
The links in the short comment tree below (which answered essentially the same question from just a few weeks ago) might be useful here:
https://news.ycombinator.com/item?id=40455815