10 maps that explain Russia's strategy - Business Insider
I found this article very interesting. It lays out in very clear terms the role that Ukraine/Russian geography plays and the dynamics of Russian geography. In particular was one pair of maps that showed the boundary of the German advance in 1942:
vs the current map if Ukraine is considered to be unfriendly to Russia:
Basically you could see a Russian mindset that they have lost nearly as much over the last 20 years as Germany took in 1942.