I think its possible the passport "power" index is a 2nd remove measure of the amount of latent and overt hostility in the world by power-camp.
It's very likely a core set of economies mutually agree to decline passports from specific economies, much at the same time.
Within that, there are inter-economy microaggressions which last for generations: if you ever visit India, be prepared to be asked about your patrilineal and matrilineal heritage back to pre-1949 in some detail, so they can "ban you for being Pakistani, without having to ban you for being Pakistani" -And the historical behavior over recognition of east germany, or visitors to Israel who then subsequently visit e.g. Jordan
It's very likely a core set of economies mutually agree to decline passports from specific economies, much at the same time.
Within that, there are inter-economy microaggressions which last for generations: if you ever visit India, be prepared to be asked about your patrilineal and matrilineal heritage back to pre-1949 in some detail, so they can "ban you for being Pakistani, without having to ban you for being Pakistani" -And the historical behavior over recognition of east germany, or visitors to Israel who then subsequently visit e.g. Jordan