A bit more specific than “Federal government”.
China is the biggest creditor to the U.S. - everyone knows that. But, do a little research on Saudi and Gulf States stakes in the U.S. economy as a whole. It can be a challenge since they often go through 3rd parties. Though one could look at more obvious ones to begin with.
I don’t think it has to do with the Debt. I think it is more personal, like the Bush Family being “friends” with the Saudi Royals.
And we know they have mastered lobbying...