Cambodia doesn't get a lot of attention on the world stage, but it deserves a closer look because of the way its economy has quietly exceeded expectations in recent years. Growth has been running at near double-digit rates over the last decade, and the country is attracting significant foreign investment, particularly in the textile and tourism industries. A big part of this success is due to its use of the U.S. dollar as its primary currency.

The government didn't orchestrate this monetary reform; in fact it resisted most...