The topic of “NATO expansion” was not discussed at all, and it wasn’t brought up in those years. I say this with full responsibility. Not a singe Eastern European country raised the issue, not even after the Warsaw Pact ceased to exist in 1991. Western leaders didn’t bring it up, either. Another issue we brought up was discussed: making sure that NATO’s military structures would not advance and that additional armed forces from the alliance would not be deployed on the territory of the then-GDR after German reunification. Baker’s statement, mentioned in your question, was made in that context. Kohl and German Vice Chancellor Hans-Dietrich Genscher talked about it.
Everything that could have been and needed to be done to solidify that political obligation was done. And fulfilled. The agreement on a final settlement with Germany said that no new military structures would be created in the eastern part of the country; no additional troops would be deployed; no weapons of mass destruction would be placed there. It has been observed all these years. So don’t portray Gorbachev and the then-Soviet authorities as naïve people who were wrapped around the West’s finger. If there was naïveté, it was later, when the issue arose. Russia at first did not object.
https://www.rbth.com/international/2014/10/16/mikhail_gorbachev_i_am_against_all_walls_40673.html
Mit dem Angriff auf die Ukraine hat Russland das Völkerrecht und folgende Verträge gebrochen:
https://de.wikipedia.org/wiki/Budapester_Memorandum
https://de.wikipedia.org/wiki/Russisch-ukrainischer_Freundschaftsvertrag
https://de.wikipedia.org/wiki/Russisch-ukrainischer_Grenzvertrag_2003