If it’s the “official” currency, yes it will happen. It’s the alternative to printing and managing your own currency, and probably cheaper. (If there are counterfeiting issues, presumably you’ll get plenty of help from outside police forces).
In many countries the bills are made of plastic. and hence much more durable than the paper US bills. (Canadian bills include a transparent strip and a hologram).
Encourage anyone flying to another country to get US currency from airport ATMs, then stock those ATMs with the oldest cash you have. Done! Make these ATMs fee-free, or something, and people will think they’re getting a deal.
It’s even cheaper to not do it at all. My understanding (and I’ve never been to either Ecuador or El Salvador, where the US$ is the official currency) is that the bills that circulate in those countries are mostly very worn out. However, if someone has first hand experience, I’m prepared to be corrected.
BTW, I also understand that the $1 coins circulate much more in these countries than in the US.
Would that fall under the same reporting requirements, IRS interest and susceptibility to civil asset forfeiture (Why do you need so much cash? You must be doing something illegal.) as US residents? Or would it go through separate channels like the Treasury?
This is one of those “fun facts on the internet”, so take it with a grain of salt; but I remember reading that at the time they switched over to the Euro, the Dutch had an entire soccer field covered in old guilder notes and coins, that they had to dispose of.