> Everyone thinks they're on the right side.
In this case that has been made pretty easy to see. Even large numbers of Russians agree with that.
> Now, obviously I think we (as in EU+US) are the good guys here, but it's quite clear that a lot of people were both very convinced and very wrong about this and I don't consider us unfailable.
Indeed. But this isn't the Cuban missile crisis (which was provoked by the USSR to begin with) and the Ukraine isn't anything like Cuba.
Note that Cuba was - in spite of everything - never actually invaded with the intent to occupy, and it's not as if the US couldn't have done that if they had wanted to do so.