And confidence can vanish like a pile of feathers in a hurricane. When the psychology that has placed the US on the same pedestal the Japanese were on in the late 80s changes, you could see a collapse of the dollar. It has the makings of a disaster of historic proportions, although, for the moment, the dollar is still king. One reason for that is that the dollar is ubiquitous, and therefore the only real contender in the tripolar currency world it inhabits with the yen and the euro. Yen are really only used in Japan, euros are really only used in Europe.
Dollars are absolutely everywhere.
At least the dollar is the liability of a specific government, which has sovereign control over a specific group of taxpayers it can fleece to meet its liabilities. The Euro is a construct as artificial and unstable as the old Soviet Union. But, since perception is reality in the financial world, people are perfectly willing to use it as a medium of exchange and a store of value. The problem is, however, that it s not nearly as widely known, accepted or trusted a medium of exchange as the dollar. And its record as a store of value has been dismal so far.