They say:

"This “sterilization” of unwanted financial speculation is precisely what the United States has criticized China for doing. China has tried more “normal” ways to recycle its trade surplus, by seeking out U.S. companies to buy. But Congress would not let CNOOC buy into U.S. oil refinery capacity a few years ago, and the Canadian government is now being urged to block China’s attempt to purchase its potash resources. This leaves little option for China and other countries but to hold their currencies stable by purchasing U.S. and European government bonds."

Or, it may force them to take {WAR!!}what we won't allow them to buy....hmmm didn't we force Japan into a similar box pre WWII??