When President Bush plays host to China's leader Thursday, their lunch chat will probably be more about currencies than current events. Hu Jintao may try to tell Mr. Bush that China can't allow a free market to rule over its yuan.
A Chinese currency kept at such an artificially low exchange rate that "Made in China" goods flood US stores and underprice American manufacturers is as critical to the survival of Mr. Hu's Communist Party as is political stability in China.
Letting the yuan float on world markets, as Hu may argue, will not continue to create the kind of export wealth in China that is needed to avoid more peasant uprisings (an almost daily event in rural areas).
Will Bush humor Hu?
Or will the president instead push the Treasury Department to brand China as a "currency manipulator," as might happen soon after the visit? (Treasury must make semiannual reports on China's foreign-exchange controls, which now help keep the yuan undervalued by 20 to 40 percent.)
Public pressure in Congress to lessen China's negative effects on the American economy could force Bush to charge China with anticompetitive behavior. That would mainly mean more loss of face for Beijing and not much in real sanctions.
Either way, some in Congress threaten to pass a bill that calls for a cutoff of loans to China from international development banks if the present controls on the yuan remain.
Coming only months before a US election, Hu's visit has put Bush in an awkward spot. (The visit was originally scheduled for last September, but hurricane Katrina forced a postponement.) To avoid more pressure from Capitol Hill, the president may have delayed the Treasury report until after Hu's departure. The White House did structure the trip as something less than an official state visit.
Even as a reluctant host, Bush needs to send a signal that China's immense clout in global markets - its economy is growing at 10 percent - requires that it not isolate the yuan.
Last July, China did allow a slight but controlled flexibility to the yuan's value, but hardly enough. And last week, it raised the dollar amount that Chinese can spend overseas from $8,000 to $20,000, and allowed a similar rise for Chinese firms. This is a small but backdoor way toward currency freedom.
Also last week, though, China beat out Japan for the first time to become the world's largest holder of foreign reserves ($875 billion). And last year the US trade deficit with China topped $200 billion.
The ratio of US imports from China compared to exports to China is now 6 to 1. That is twice as high as the ratio during the height of US-Japan trade frictions in the 1980s.
Hu needs this visit to go well to prove to party rivals that he can manage China-US ties. That will boost his authority before next year's party congress. But his slogan for China - "peaceful development" - isn't keeping economic peace with the US.
As inward as Hu's focus may be, he can't ignore the fact that China can't rely on free trade to thrive while denying free trade for the yuan.
China is like a bull in the global trade shop. The US needs to persuade it to be more like a customer.