The "foreign reserves" that most countries uses to value their country and their own currency are US dollars, Japanese Yen, and the Euro.

Which of these countries or group of countries are not in big pile of debt?

So if I were any other country, would I want to base or put my country's money into these becoming worthless paper? Reminbi isn't international currency yet. There is no strong currency out there right now. Next best thing? It's gold. Everyone values gold. Problem with gold is that you can't print more of it suddenly.