I'm not sure if he's using an esoteric definition of "national government", "English speaking", or "default", but if you consider the "Failing to make a payment on a US government issued bond as agreed" then he's wrong. The US failed to pay out on inflation-adujsted WWI War bonds (paying them in nominal dollars rather than gold contrary to the bond terms, a substantial haircut) and during a previous unprecedented debt ceiling crisis in 1979 the US tried to dance too close to the edge and wasn't able to pay all the bonds due on time.

http://en.wikipedia.org/wiki/Liberty_bond#Default_of_the_Fou... http://www.npr.org/2011/07/11/137773341/looking-at-when-the-...