-—We can print out enough bills to pay our debts tomorrow if we wanted.
It would cause massive deflation-—
Wouldn’t that be inflationary?
-—but nothing as bad economically as a default would bring.-—
As to why, because it could be done gradually, and it would not be a breach of the promise our nation gives when we borrow money, which will count for a lot when we need to sell our goods overseas.
Moreover a default by us would trigger a default by everyone else. Welcome to worldwide depression!