For many in China and Britain, it is a dark moment for China-Britain relations when Prime Minister David Cameron chose to meet with the Dalai Lama despite strong Chinese opposition.

The move not only tears open an old wound that has healed to a large degree in the past few years as the two countries have been working hard to shelve political differences and build a constructive partnership in the face of the global financial crisis.

It also reverses the positive momentum in the bilateral relationship carefully fostered by friendly high-level exchanges of leaders of the two countries in the past couple of years.

China has long made it clear that the Dalai Lama, who has for decades been engaged with activities aimed at separating Tibet from China, should never be hosted by leaders of other countries.

Any meeting, private or official, is interpreted by Beijing as a kind of endorsement for the anti-China secessionist and a blatant interference in China's domestic affairs, which will inevitably lead to strained bilateral relations.

For Western leaders who cozy up to the Dalai Lama, their political calculations are pretty simple.

They do want to build a positive relationship with China, a promising export market and an increasingly credible partner in international affairs. But too often they also fall victim to the incorrect assumption that giving audience to the Dalai Lama could prove their moral clarity and help score easy political points at home.

The calculations are dead wrong because essentially the Dalai Lama is never what he claims to be.

Furthermore, they are wrong also because Western leaders cannot have it both ways when they have to choose between a sound relationship with China and unnecessary provocations like meeting with the Dalai Lama.

For Cameron, he has to bear in mind that China would not sit still while its core interests are trespassed on.

It is impossible for China to buy any excuses of such meetings, which should not happen under any condition, even though the British government claimed that it was a "private" occasion and Cameron is free to meet with anyone he chooses.

Also, there will never be a happy ending when a country works with China to seek economic and trade benefits on the one hand while on the other hand crossing over the line from time to time on issues concerning China's core interests, including the issue of Tibet.

China has always held a sincere attitude in cooperating with Britain as well as other Western nations, especially in this time of eurozone debt crisis and global economic slowdown.

Meanwhile, President Hu Jintao, Premier Wen Jiabao and other Chinese leaders have expressed on many occasions their confidence in the European economy and pledged to help revive its sluggish recovery.

The British leader needs to know that turning a deaf ear to China's protests would only backfire in the end, overshadowing the development of bilateral ties and cooperation, which is even more important to Cameron's political future.

The damage on China-Britain ties has been made. And the key to restoring the bilateral relations to normality is now in the hands of Cameron and his government. It is highly advisable that proper actions be taken as soon as possible so that negative ramifications can be eliminated once and for all.

(Xinhua News Agency May 16, 2012)