US President Barack Obama's trip to China had come to an end, but the debate on the Taiwan policy of the United States is still on.

During Obama's visit, the world's biggest developing nation and the most powerful developed country issued a joint statement, vowing to respect each other's sovereignty and territory integrity, without making mention of the Taiwan Relations Act (TRA).

The joint statement worried Taipei so much that Raymond Burghardt,chairman of the American Institute in Taiwan, made a quick flight to Taipei to soothe those anxious nerves, pledging that his country hasn't changed its Taiwan policy and the TRA which requires the US to sell defensive arms to Taiwan is still the central pillar of US-Taiwan relations.

Burghardt's remarks met with deep appreciation within Taiwan, but sharp criticism across the Taiwan Straits. The US Taiwan policy looks self-contradictory. Is it just the two-pronged strategy US is pursuing in the past years? Maybe not.

Actually, the US Taiwan policy is at the crossroads of an reevaluation. On the one hand, the US needs China's help to deal with major global issues. On the other hand, the current US-Taiwan relations have been maintained for nearly 30 years, so it is not easy to change.

Firstly, it is a continuation of the joint efforts to contain "Taiwan independence" by Beijing and Washington since 2005. In Chen Shui-bian's second term, Taiwan authorities' efforts to seek "de jure independence" through the so-called "constitutional reform" entered into a substantive stage, which involved the possibility of changing the "territorial definitions" of Taiwan. These activities had actually threatened the Cross-Straits relationship and the peace and stability in this region, aroused firmly criticism from the mainland from the outset, and the United States joined into the criticism later. From then on, Beijing and Washington have established a united front to some extent to contain the "Taiwan independence."

Meanwhile, recognizing China's sovereignty and territory integrity is the core spirit of the three joint communiqués, which are the Shanghai Communiqué endorsed in 1972, the Joint Communiqué on the Establishment of Diplomatic Relations in1979 and the Sino-US Joint Communiqué in 1982.

Secondly, the US has no choice but to change its Taiwan policy if it wants to win Beijing's help to deal with the global issues. China, America's top creditor, is expected to replace Japan as the second largest economy, while Uncle Sam has his hands trying to extricate himself from Iraq and Afghanistan.

So, the US needs to strengthen ties with Beijing in an effort to resolve the global financial crisis, foster collaboration on climate change and curb nuclear proliferation in North Korea and Iran. Beijing's cooperation is also essential on a range of other urgent issues, including terrorism, public health and energy supplies.

Thirdly, Obama's foreign policy is quite different from that of the previous administration. In Obama's presidential campaign, "change" was the most fashionable word. Since his inauguration, the United States foreign policy has indeed changed a lot, and the Taiwan policy should be part of the change.

Of course, some stubborn US strategists still believe it's necessary to contain Beijing's rise, and backing Taiwan is the best choice. As the saying goes, Taiwan is the unsinkable aircraft carrier. So they insist US should not abandon Taiwan.

However, the new situation is overwhelming. The forces that advocate a closer relationship with Beijing is growing in the US and Taiwan shouldn't to be the obstacle. With the rise of Beijing, Taiwan's status in Sino-US relations will be lower and lower.

The author is a researcher with the Institute of Taiwan Studies, Chinese Academy of Social Sciences.