If a major superpower falls ... I don't think you can say there's a general "rule" like this, throughout history. If anything the cases where these powers bec

If a major superpower falls ... I don't think you can say there's a general "rule" like this, throughout history. If anything the cases where these powers become straight-up subjugated from the outside (absent outright military invasion) are in the minority. Counter-examples abound, e.g. the Ottoman Empire and Austria-Hungary, or Spain after the disaster of 1898. See Russia after the fall of the USSR, but before Putin. Post-Soviet Russia was weak for sure, but not a vassal state by any interpretation.