If only this had a more complicated explanation than something akin to schoolyard drama.
> NATO largely stopped that by putting them under a common umbrella.
You're thinking of democratization, the end of imperialism, and the elimination of aggressive regimes. Helped along by the financial devastation caused by the war.
> I don't think Russia is broadly hostile to the world.
Sure, unless you listen to all of their broadly hostile rhetoric or are on a Malaysian or Azerbaijani airliner or something.
> This inevitably sets the stage for geopolitical conflict
This your way of saying Russia needs to cut undersea cables and invade neighbors?