Do you not think that the US has a huge sphere of influence? It seems to me that the US can and does take any action it wishes to outside its borders. Sometimes those actions have a good moral justification and sometimes they don’t.

>US and Russia simply can not agree between themselves what should be Ukraine's place in the world.

I’ll argue the opposite. The Ukraine has no inherent right to join NATO. Ukraine isn’t going to join NATO unless the US wants it to join and this is morally correct in every way considering the obligations of article 5. Additionally every other NATO member has the right to veto expanding the alliance (this is fact btw not opinion).

Additionally the US has every right to negotiate with Russia over Ukraine joining should the US wish to.