I'm not an alarmist by nature, but the numbers are what they are. No country can run 5% current account deficits forever, while systematically underinvesting relative to its leading competitors. (Budget deficits are different. The US Treasury can always print greenbacks if it has to. But the US Treasury can't print euros or yen.) Sooner or later, the bills will come due, and then the US will suddenly become 25-35% poorer than it nominally is. It doesn't have to mean a Great Depression; it could just mean a 30% appreciation of the East Asian currencies (say, 85 yen to the dollar).
-- DRR