While relations between China and the United States are much improved from a year ago, there remain several prickly issues that divide the countries. President Bush is expected to touch on some of these issues on his visit to Beijing next week.
Chinese Foreign Ministry spokesman Kong Quan says President Bush's visit will further warm Sino-American relations. He says the talks will help the two sides make progress on many issues.
Many are contentious. U.S.-based Brookings Institution China scholar Nick Lardy says the differences may overshadow the new Chinese-American partnership that followed September's terror attacks. "I think the alliance against terrorism is much more tenuous, and there are still fundamental underlying problems in the bilateral relationship that stand in the way of very close cooperation," says Mr. Lardy.
One of those underlying problems is stopping the spread of advanced weapons technology from China to other nations, including Pakistan. Mr. Lardy says China has not kept a November 2000 agreement to stop exporting technology for missiles capable of carrying nuclear weapons. Washington argues that giving the technology to Pakistan makes a catastrophic war more likely with its nuclear rival, India.
Those weapons exports earn China political influence and money, making some officials reluctant to stop the trade. But Zhu Feng, head of security studies at Peking University, says Beijing is rethinking weapons exports, worried that they damage relations with the United States, or that the technology might fall into the hands of China's enemies. "I think the Chinese government's attitude toward non-proliferation has changed very substantially. Now, an increasing number of Chinese realize that proliferation will [be] finally threatening to China," he says.
Human rights is another tough issue in Sino-American relations, particularly on religious matters. China's Communist Party allows only approved groups to worship. Many unapproved groups have been banned as "evil cults," including the Falun Gong spiritual movement.
While the two sides are far apart on human rights matters, analysts say Beijing is showing new signs of flexibility on Taiwan. Chinese Vice-Premier Qian Qichun recently invited members of Taiwan's ruling party to the mainland for talks. Analysts call that a step forward, compared with the previous policy of ignoring the island's elected leadership.
Former U.S. ambassador to China Jim Lilley says China's economy is growing strongly, while Taiwan is in a slump. He says that situation makes China's leaders more confident and less belligerent toward Taiwan. "The economic dimension has become overwhelming," he says. "There is not talk about using military force on Taiwan. There is talk from the Chinese side about time being on their side."
Taiwan split politically from China after civil war in 1949, and has been ruled separately ever since. China has threatened military action, if Taiwan declares independence. Washington has pledged to support Taiwan, if China makes an unprovoked attack.
The lowering of tensions over Taiwan is seen by analysts as part of China's campaign to improve relations with Washington. That effort saw China offer quick political support to the U.S. war on terrorism and play down the embarrassing discovery of high-tech listening devices in President Jiang Zemin's U.S. made aircraft.
Over the next couple of years, China faces political strains from an expected leadership change and the economic dislocations that follow Beijing's admission to the World Trade Organization. The leadership in Beijing apparently does not want its successors to have to deal with an angry United States on top of these economic and political problems.
Analysts also say China's leaders were startled by the speed and success of the U.S. attacks on terrorist targets in neighboring Afghanistan, and are worried that such military power might make Beijing irrelevant in Central Asia. Some analysts argue that cooperative relations with the United States will help China influence events in Central Asia, which is important to Beijing because of the region's oil reserves, needed to fuel China's continued economic expansion.
China's president, Jiang Zemin, and other officials will make their points to President Bush when he arrives on the anniversary of President Nixon's visit to China 30 years ago.
Mr. Kong, the foreign ministry spokesman, says China regards Mr. Nixon's visit as an important moment in history. That visit began a process of opening up to the outside world, which in turn brought economic reform and unprecedented growth to China.
Historians say, during those 1972 talks, Washington and Beijing put aside many of their differences, because they both perceived a threat from Moscow's military and political power. Now, during Mr. Bush's visit, the two profoundly different nations again face a common enemy -- terrorism -- and are both working to improve relations.
But Mr. Bush's visit comes just before another anniversary, last year's collision between U.S. and Chinese military planes that killed a Chinese pilot and forced the American crew to land in southern China. That incident enraged some Chinese, and stopped many diplomatic and military contacts between the two nations.
Taken together, the two anniversaries show how long China and the United States have been trying to build good relations, and how easily unforeseen events can derail those efforts.