[nazcan]

This is one thing I've heard repeated - that USD needs to be spent in America - seems like other countries could just transact with it directly.

[thaumasiotes]

They can and they do; that's called dollarization.

It's worth observing that dollars that are never supposed to return to the US don't have the same anti-counterfeiting pressure that dollars spent in the US do. I don't know how much of a market there is in counterfeiting USD for dollarized economies.

[etskinner]

This sounds hard to believe. Adding anti-counterfeit messures to the bills that have them ($10s and up?) can't be that expensive compared to the value of the note, why would they make two different versions?

Not to mention, that would break fungibility.

Can you provide a source?