Why ridiculous? The treasury cannot, by law, issue more than a certain amount of debt. The politicians may change the law - but that's a vote that's yet to have been taken. Once upon a time, it would have been unthinkable for Japan to have had a lower credit rating than AAA.
Also, the US owes money in currencies other than $, which the Treasury doesn't have the power to print.
Also, the US owes money in currencies other than $, which the Treasury doesn't have the power to print.