Given that the United States debt is denominated in US dollars and our government can technically print as many US dollars as it needs, we should never default on our debt. The only way we could truly default would be if Congress, in an incredible act of stupidity, decided to vote to default and overrode a Presidential veto. Traditionally that seemed so obviously idiotic that markets had no fear it would happen. But that all changed last year when Republicans decided to hold the vote to raise the debt ceiling hostage to their budget reduction demands.