Having a relationship based on mutually beneficial economic exchanges is an important reason why one would treat their economic partner nicely. It’s perhaps not the reason, but it is a reason.
Given how peacefully it collapsed and the huge potential for mayhem, I’d stay away from altering the timeline.
We have no idea what the alternate histories would look like. We can guess - yours is a reasonable guess - but it is all guesses. I can come up with reasons thing would things went far worse, and if you think a little you should be able to as well - they may be somewhat unlikely, but that is all the more we can say.
What we do know is where we are today: Russia is not playing nice with the world despite our attempts to have beneficial economic exchanges. Would the not play nice with USSR scenarios be worse - we have no real idea.
Given how peacefully it collapsed and the huge potential for mayhem, I’d stay away from altering the timeline.