What should have been a stirring symbol of sporting excellence, the triumph of human endeavour, and of international camaraderie is turning into a lightning rod for controversy. The Olympic torch arrives in London tonight from St Petersburg surrounded by bickering suspicion and anger. Those who condemn China's behaviour in Darfur and Burma and Tibet - and we report today that eight people have been killed by Chinese paramilitary forces who opened fire on Tibetan monks and villagers protesting against confiscation of pictures of the Dalai Lama - have every right to use the torch's progress through London tomorrow to protest against Beijing's human rights record. Indeed, thousands of demonstrators are expected to line the torch's route. The officer in charge of the operation, Commander Bob Broadhurst, says he “will facilitate all lawful protests”, and has promised no repeat of the tactics used during visit by the Chinese Premier in 1999, when placards were seized from demonstrators to spare Beijing's blushes.

But hand in hand with this newspaper's unwavering support for the democratic rights of law-abiding protest goes our wholehearted backing for the smooth progress of the Olympic torch along its 85,000-mile journey across the world until it returns to China, there to inaugurate a landmark event for both sport and also for China's emergence into the blinding, often unforgiving glare of world scrutiny. China has a right to host these Games without the threat of boycott. It is vital to keep in mind that the Olympic torch is not about China. It is about the Olympics and about the athletes competing in them. For those reasons we should respect and honour the torch as it crosses the capital. The Games are a cradle of fierce rivalry and also of international friendship; an arena in which to showcase both human endeavour and also human solidarity.

As it threads its way through the world, the torch sews together countries that may not always see eye to eye, binding them with novel bonds of fellowship. We should embrace the way the Games offer countries with festering grievances against neighbours an opportunity to break bread with each other without also wanting to break each other's heads. Such was the vision painted by Liu Qi, president of the Beijing Olympic organising committee, when he greeted the flame's arrival in China this week with a pledge that: “The burning Olympic flame will spread the message of peace and friendship and unite all people under one world, one dream.” It echoed a remark Mr Liu had made seven years earlier, that: “If Beijing wins its bid to host the Olympic Games, it will be conducive to China's economic and social progress; at the same time it will also make further progress on the promotion of human rights.” Mr Liu must be given a chance to show that he is as good as his word, and to demonstrate that China is hosting a coming-out party in August that we will all rejoice to attend.

The alternative - calling for a boycott that frustrates athletes and humiliates the Chinese - is not only short-sighted, but self-defeating. If the West ruins China's great celebration of its modernising, reforming, internationalising self, the Chinese people will not only lose face, they will turn their faces against the world. It is far more constructive to make a plain and public case endorsing China in its efforts to host a successful Olympics, and using the opportunity that creates to agitate for an improved human rights record and a more responsible foreign policy. The Beijing Olympics offer an unparalleled opportunity to offer a hand of friendship to China. China is smart enough to know that such friendship often comes at a price; that Beijing will be the focus of huge international inspection, and that such attention will not always be flattering. But the West must capitalise on this opportunity with diplomatic grace and ingenuity, rather than with a form of diplomatic Tourette's.

The Olympic torch is a modest object, barely bigger than an upright baseball bat. But its flame stands as a potent symbol of what the world might, ideally, one day become - not necessarily just what it is today. Snuff out that flame and the world becomes not brighter, but darker still.