@Max5 - dear Max, may I suggest you do a brief synopsis of the article in the link, as I think most people do no longer click on links. It contains valuable information which was news to me and I think I am reasonably well informed.
The most pertinent of which - if I may - is; that a promise of further NATO encroachment east was made to and with the former Soviet Union and it became null and void after Glasnost (ref: NATO-Russia Founding Act of 1997) and a newly formed Russia and its diverse nations had formed. There is no such contract, no such promise and it can therefore not be broken.
I apologise if I did not formulate this properly, so please correct. Taurisk