... i'd invite North Korean dictator Kim Jong Il and his government to some sort of friendship and solidarity gathering. After they arrive, announce that they've all decided to retire to the Gobi desert to pursue their long-neglected interest in dinosaur fossils and that they ask everyone to respect their desire for complete and perpetual privacy in this endeavor.
Then give North Korea to South Korea. Within a year the South Koreans will start agitating for the US to pull its forces out. With the North Korean threat gone and with money tight, the US would just about have to.
Two problems solved for China.