Slippery slope dictates it has to start somewhere. Remember how in the West we went from "Look just ignore them, let them do whatever they want in their own bedrooms" to "Pedophilia is a legitimate sexual behavior, children can totally choose their own sexualities too"
Taking this logic to its end conclusion, it suggests that if any politician as much as says one mean word about another country, that means tanks are soon to follow. I don't know where that happens, but probably it's not our reality. It generally takes a whole lot more than that.
I disagree; you could just as easily argue that continued NATO expansion, after the supposed end of the Cold War, created a self-fulfilling prophecy by causing Russia to believe that peace was never an option, and future conflict with America and Europe was inevitable.
Russia cannot at the same time believe and disbelieve that peace is an option. Especially conveniently acting according to former when it gets another trade treaty, international initiative, diplomatic favor or something other from western powers, but surprisingly forgetting that and going to the latter when it comes to dealing with neighbors.
Seems to me like Russia's memory about claims and grievances is selective, and not just randomly, but in a very clever and convenient way. When the West was willing to extend trust to them, give them favors and admit it to trade deals and so on, everything was fine, they were willing to say yeah, no claims there, we're all sovereign countries, you can even have that in writing... but the moment Russia feels a bit stronger it turns out all these things that were ok before are suddenly a security concern for Russia that no one mentioned when it could have broken the deals. Let's be honest, if Russian politicians told Ukraine and western countries the same opinions on what they think on Ukraine's sovereignty and what actions it cannot do under threat of military intervention as they do now, Ukraine would have never given up nuclear weapons.
And considering that Russia, UK and USA signed off on that deal and its security clauses, it's a very awkward situation for all the other parties regarding their relations with Russia.
Long story short, if Russia wants to deceive other countries on what its true claims, ambitions and expectations are regarding its long term relations with them, it deserves everything coming to it out of the chaos caused by playing games like that.
If Russia considered NATO expansion such a massive and non-negotiable dealbreaker, it should have put that in clear writing and refused to sign things like the Budapest Memorandum in their existing form and made such expectations clear from the start. Maybe things would have went differently. Maybe the conflict would have happened much earlier. Maybe not at all. Maybe they would be signed in the end, but Russia would have had to make major concessions in other areas, or would not have gotten some very profitable deals with EU members.
But even if it is honest about those concerns, which i doubt, then the grand deception about their non-existence in the past deserves its own punishment and in its own right can be considered a perfidious and hostile move.
