I'm sure Visa, MC and Amex incur fees for settling USD amounts outside US, repatriating or remitting USD to make up differences.
But only MC passes it on.
Interchange is not directly affected by the country of the cardholder. I understand it has more to do with the country of the merchant - the issuer gets the merchant's home interchange rate, which may be higher or lower than the US.
I see little justification for the fee.
But as noted in fatwallet it's not something you can chargeback against.
I'd use cards with known foreign transaction fees sparingly for foreign-based merchants, in case they pull something like merchant country processing (even if the amount in cardholder currency is correct) to save costs.