"In 2003, the most recent year with full international statistics, central banks financed 83 per cent of the US current account deficit, with Asian central banks accounting for 86 per cent of flows.
A similar picture is emerging for 2004. Despite a good start to the year, when the private sector was a large net purchaser of dollar assets, central banks came to the rescue again. The People's Bank of China has let it be known that China increased dollar reserves by $207bn (€159bn) in 2004, financing nearly a third of the US current account deficit, estimated at $650bn."
And if large investors decide that Euros are the better option...?