Since these debts are paid back, with interest there is no way it could be interpreted as tribute.

Not true for treasury bonds, they roll them over rather than paying them down. The (likely temporary) special status of the dollar in international trade imposed after WWII also means that it is in high demand outside the US, giving us a special place as the source of dollars which can get extra stuff for them.

Regardless, end result is still more stuff for Americans.