Having pulled off a diplomatic coup on Taiwan, avoided a row over trade and generally furthered his reputation as a man of the people, Premier Wen Jiabao can feel well satisfied with his four-day visit to the US. But while the trip might be viewed as a victory for China, its success lies in the strengthening of the relationship between the two countries and their understanding of the need to work together. This is the basis upon which this week's events should be judged. The Taiwan issue demonstrates, at the very least, a new sensitivity on the part of the United States government towards the interests of the mainland. President George W. Bush broke with the past by expressing clearly his opposition to moves by Taiwan towards independence. While delicately worded, the statement signalled that America's long-standing policy of calculated ambiguity on cross-strait relations has suddenly become rather less opaque. He warned President Chen Shui-bian not to push the independence agenda, a clear reference to Mr Chen's provocative 'defensive referendum' planned for March. Whether this represents a major shift in policy, as some have claimed, remains open to doubt. As the administration has been quick to point out, the statement is consistent with the traditional position that the US does not favour any unilateral change to the status quo. However, in the past US presidents have carefully avoided using the word 'oppose' to describe their position on the question of Taiwanese independence, and the use of that loaded word on this occasion is of considerable significance. At this stage it is only a semantic difference. Already, Mr Bush is under pressure from conservatives to address different, and softer, words towards Taiwan. There is no sign that the US will stop selling weapons to the island or go back on its legal obligation to defend it. Nevertheless, these latest remarks highlight the change that has taken place in the three years since Mr Bush came to power. No longer do we hear him talking of doing whatever it takes to defend Taiwan. Those within his administration who favour a closer relationship with the mainland would appear to be in the ascendancy. And Mr Bush now appreciates that preventing cross-strait hostilities is a priority for the US. In the current climate, that means standing with the mainland in seeking to rein in Mr Chen. Trade was another sensitive issue for Mr Wen to tackle, amid pressure in the US for China to free up its market and revalue the yuan. The premier dealt with this deftly, making conciliatory noises without committing himself to any radical concessions. It was sufficient to prevent the trade issue tarnishing the trip. Mutual interests, expressed in terms of the growing volume of trade between the two countries, were again to the fore. As for Mr Wen himself, he has succeeded in furthering his reputation as a leader with the human touch. Shaking hands with the public, making jokes and speaking emotionally about his childhood, he conveyed a rather more open, accessible and humble image than previous Chinese leaders. He may have stumbled at the Harvard Business School when tackled about the prospect of democratic reform. But if the students were disappointed Mr Wen did not present himself as a trailblazer for the rapid introduction of universal suffrage, that is because their expectations were unrealistic. What has been evident during this trip is the extent to which the strategic interests of China and the US have become entwined, and the appreciation of this on both sides. Maturity was a word used by both leaders to describe the relationship. Whether on trade, Taiwan or anti-terrorism, the superpower and the emerging power know they need to work together.