The Chinese Foreign Minister's euphemism was long and unsubtle. “I shall assure you that our Government is fully capable of maintaining social stability and ensuring the security of tourists,” he said yesterday, even though the security of tourists is a minor issue in the anti-Chinese unrest spreading outward from Tibet. The real issue is the apparent killing, jailing and forced confessions of Tibetan protesters, and the minister's real meaning was that his Government is fully capable of flooding even the vast Tibetan plateau with troops and tanks.

Beijing's brute strength is not in doubt as it confronts the most significant challenge to its authority in a generation. But the mile-long military convoys seen winding into the mountains from western China in recent days are an entirely inadequate response. Thousands of Tibetans, first in Lhasa and now to the north and east in Gansu, Sichuan and Qinghai provinces as well, have siezed the unrepeatable opportunity of the 2008 Olympics to force their 50-year-old demand for autonomy to the top of the global agenda. China, for its part, seeks simultaneously to crush the protest, impose a news blackout and save the good name of the Olympiad on which it has staked more than £20 billion and its international reputation. It cannot succeed on all three fronts at once. Galling as it may seem to the world's next superpower, accustomed already to Western docility in matters of trade and diplomacy, the time has come for Beijing to sit down with the Dalai Lama and negotiate a new status for Tibet.

The last serious threat to Chinese rule in Lhasa was a two-year crescendo of demonstrations starting in 1987. It was met eventually with mass jailings, the imposition of martial law and forced “re-education” of many of the monks who still embody Tibet's spiritual identity. The context of the current crisis is fundamentally different, for two reasons. First, a technological revolution has made it virtually impossible to seal off an area four times the size of France from foreign media. Where every mobile phone is also a camera and a texting device, the telling images and facts will get out in the end. Secondly, China has undergone two decades of headlong economic development. It is this triumph of capitalism within a rigid one-party state, not the brilliance of its synchronised swimmers, that Beijing seeks to parade before the world in August. In return for the chance to do so it has already guaranteed visas for all accredited foreign press covering the Games. It may also have shown relative restraint, so far, towards Tibet's protesters.

The Tibetan government-in-exile claims 99 people have been killed by Chinese troops since last week's riots in Lhasa. Beijing puts the death toll at 16, with 325 injured, many of them Han Chinese. Whatever the truth, it is already bloody, and the bloodshed will escalate if the separatist unrest spreads north to Xinjiang, where the Muslim Uighur minority has long sought independence, through violence if necessary. But the need to save the Olympics is already forcing Beijing to be more measured than it might have been, and it is not too late to prevent a descent to the scale of violence seen in 1989. All Western governments, not just Britain's, must make clear that on the future of Tibet the Dalai Lama has moral authority where Beijing has none - and that if it fails to accept this the Olympics are at stake.