BTW "Declaring your neighbor "politically unstable" and presenting yourself as its savior was the clearest way in the 20th Century to declare war without any casus belli" is not really true, sometimes this happened, but wars have been declared for all sorts of putative reasons, like "our particular minority is being oppressed" or "the neighbouring government plotted against the life of our sovereign" or "they are infidels, go get them".
Anyway I don't really see what you propose. Binning expressions because someone someday used them in bad faith, in the belief that this will stop future invasions from happening?
This seems to be somewhat futile to me. Invasions aren't fundamentally caused by words. Words only work as a cloak and one cloak can be easily substituted by another, and it will, depending on the current state of politics in the invader and invadee country.
Note that the Russians explained their invasion into Ukraine by calling them "fascists". Should the Western civilization drop the word forever because of that?