There are three likely outcomes to the talks launched yesterday in Pretoria on the future of Zimbabwe. One is deadlock. The others are agreements to form a government of national unity or a transitional administration leading to an exit from power, at long last, for Robert Mugabe.

In the long term only one of these is acceptable for Zimbabwe's people and their neighbours - Mr Mugabe's exit. But that these talks are happening at all is progress.

Negotiations will be tinged with the surreal: Mr Mugabe's representatives will be ensconced with people from whom he stole an election and against whom he sanctioned a campaign of murder and intimidation. Their host will be President Mbeki of South Africa, who needs a just outcome for the sake of his reputation, but for years has shown himself too weak to press for one.

It would be easy to suppose that the context for these talks changed suddenly when Morgan Tsvangirai shook Mr Mugabe's hand on Monday. Could Mr Mbeki the ditherer now find the courage to be a peacemaker? Has Mr Tsvangirai, the bruised and battered opposition leader, revealed himself to be a man of compromise at heart? Did Mr Mugabe, in that instant, swap dictatorship for power-sharing?

The Harare meeting has produced a ceasefire on the streets and allowed aid agencies to go back to work. In other respects the moment of the handshake was less than pivotal. What has changed, in the past few weeks rather than days, is that the tide of rhetoric and opinion in the region has turned against the Mugabe regime; Mr Tsvangirai has been emboldened by recent events in Kenya to pursue dialogue with his old rival as a prelude, he hopes, to government; and Mr Mugabe has recognised, sooner than many of his henchmen, that he cannot cling to power indefinitely while his economy succumbs to hyperinflation and his people to famine.

Mr Mugabe hinted four months ago that he was open to standing down if a face-saving formula could be found. The signs are that he still is. The challenge for those meeting in Pretoria is to find such a formula and make sure he accepts it.

The price of such a resolution would be high. It would diminish the chances of Mr Mugabe being held accountable under international law for crimes against his people, as this newspaper has argued and will continue to argue he should be. It would also probably involve the continuation in power of elements of Mr Mugabe's party,

Zanu (PF). But if the alternative is continued political stalemate, economic paralysis and human suffering on an almost biblical scale, it would be a price worth paying.

Mr Mugabe may believe he is negotiating from strength. In fact he is as weakened as his country. Africa's other leaders are increasingly prepared to say so, and Mr Tsvangirai is reaping the political dividend. It is at his insistence that mediation at the Pretoria talks has been broadened to include other regional representatives besides Mr Mbeki. And it is evidence of his new confidence that in the framework document for the talks Mr Mugabe is described as president of Zanu (PF), but not of Zimbabwe.

Negotiations by no means guarantee peace or justice. But they have brought a pause in Zimbabwe's bloodletting and made it possible to imagine an end to the Mugabe nightmare.