John Henke is worried about the possible impact of Chinese divestment [or even diversification] on the U.S. economy:
The markets can adjust to a slow leak; a quick pop might turn the disequilibrium into an immediate crisis.
I've been wondering whether the Chinese strategy might not be to create an US dollar bubble, so that they can engineer a sudden US economic crisis at a time strategically useful to China.
I think the American position is very much stronger than Mr. Henke fears. Consider the old saying: "If you owe the bank $1 million, you have a problem; if you owe $100 million, the bank has a problem."
China's strong-currency policy impoverishes the Chinese on average, but it creates more jobs (though each is lower-paying in dollar terms). That is, it spreads prosperity as widely as possible, at the cost of it being thinner than the most successful would like. The Chinese government is structurally bound to this policy, as it is their best tool for preventing widespread unrest.
In the markets, the USD yield curve continues to invert (i.e., rates are low at the long end) -- not the action of a trading community that expects China to soon be dumping long-dated U.S. debt.