The U.S. housing market has over 9 trillion dollars of mortgage. And who are the lenders of such huge amount of money? They are the people around the world. Obviously the bankers and officials in China think that the high school dropouts, the burger flippers, and the party crashers of this country are somehow much more credit-worthy than the hard-working farmers, exploited factory workers, and desperate fresh college grads in China itself. No money down? no problem. 3% interest rate? no problem. We will lend you money so you can enjoy your house! (As long as you say Taiwan is part of China. :)
Everyone heard about the Nobel Prize winning Micro Finance in Bangladesh, right? Do you know what is the interest rate charged to lend a few tens of dollars to a hard-working poor mom who raises hens and sells eggs? 30-70% APR!
It's the trustworthiness of the United States that people around the world have been counting on.
But if dollar keeps sliding, this trust will be broken. The expectation on this self-regulating, promise-keeping and honorable economical system will be shattered. The United States will become a subprime country. And money will flee.
