From Zimbabwe's capital Harare to Quito in Ecuador, green bills circulating on the streets and in shops with images of U.S. presidents reflect a big choice that has been made: picking the dollar over the local currency to bring economic stability.

The two countries offer lessons — and warnings — for Argentina, the latest nation globally to toy with the idea of ditching an embattled local tender in favor of the greenback, a signature campaign pledge of President-elect Javier Milei.

Dollarization or the part-way option of a peg to the dollar have generally been triggered as a last-ditch option to tame hyperinflation and loss of confidence in the local currency, as was the case in the 1990s with crisis-ridden Ecuador and in El Salvador in the aftermath of civil war.