That was Feb. 25, and he never got there. His frantic wife, Liu Yingli, rang the U.S. consulate, which assured her that her husband was alive but had been detained. The latest detentions fit a pattern. The Bush administration will likely decide this month whether to sell an advanced early-warning radar system to Taiwan. China also needs U.S. support for its final push to join the World Trade Organization, and the International Olympic Committee will vote in July on Beijing's bid to host the 2008 Summer Games.
China has a history of timing the release of prominent prisoners to the political calendar.
In 1995, it paved the way for First Lady Hillary Clinton to attend a United Nations conference in Beijing by freeing human rights activist and U.S. citizen Harry Wu. Two years later it freed dissident Wei Jingsheng just as President Clinton prepared his own trip. Li moved to the U.S. with the first wave of Chinese students in 1982, shortly after Beijing launched economic reforms. His Ph.D. dissertation at Princeton dealt with China's one-child policy. But that never stopped him from returning to China frequently, and in the past decade his research has focused on China's economic reforms.