Ukraine crisis in Europe: Backgrounds

The crisis about the russian troups close to the Ukrainian boarder is really getting hot.

To understand the background, the speach of John Mearsheimer at the University of Chicago -- given September, 25th in 2015 -- is a brillant analysis of the current situation. 75 minutes on YouTube [1] worthwhile to follow!

Addendum: One other source of information is the 'Russian Aggression Prevention Act' of 2014 [2].

2nd addendum: Noam Chomsky's oppinion on that crisis [3]; dated 2021/12/23.