He grew-up in Indonesia and was adopted by an Indonesian and renounced his somewhat tenuous US citizenship.
He used an Indonesian passport to travel to Pakistan as it would have been illegal for an American.
This is a false meme. Americans were not barred from traveling to Pakistan, they were warned that it might be dangerous. An American COULD travel to Pakistan during this time, but it would have been a foolish thing to do.
That being said, I also suspect he used an Indonesian passport.