Leading article: A spiral of despair – and a ruler hellbent on destroying his country

Every time one imagines that Zimbabwe has hit rock bottom, Robert Mugabe's cruel regime manages to push the country into even greater misery. The past week has witnessed the unleashing of a campaign of violent intimidation against the political opposition. Thugs working for the ruling regime have forced thousands to flee their homes and left scores dead, including the prominent activist Tonderai Ndira.

Nor is it just the poor who are the targets. The opposition presidential candidate, Morgan Tsvangirai, has been detained by the Zimbabwean police twice this week. American and British diplomats investigating reports of repression have been harassed by the security services too. And yesterday's ban on several planned opposition rallies is the most transparent attempt yet to disrupt the run-off presidential elections scheduled for later this month. Given the ruling party's monopoly on the media, such meetings are the only way for the opposition to communicate with many of its supporters.

As well as robbing the Zimbabwean people of their political rights, Mr Mugabe seems intent on making them starve too. His performance at the United Nations Food and Agriculture conference in Rome this week where he blamed Western sanctions for the huger of his people was obscene. The most significant reason why Zimbabweans are hungry is Mr Mugabe's agricultural mismanagement of a nation that was once known as Africa's "bread basket".

Mr Mugabe unleashed a fresh hell in this area this week: a ban on the distribution of food and water by international aid agencies. One-third of Zimbabwe's population relies on such aid and about 5 per cent are suffering from severe malnutrition. The UN says this ruling will severely restrict its work. But in Zimbabwe food and politics are inextricably linked. The authorities want to control the distribution of food aid so they can withhold it from opposition strongholds. It is also a way to ensure that international aid workers will not witness the violence being used to intimidate voters in rural areas.

Yet there is an unusual recklessness about all this, even by Zimbabwean standards. Mr Mugabe does not mind the condemnation of the West, of course. Indeed, it would not be surprising if one of the reasons he travelled to Rome was to provoke it. But his allies in Africa are finding his behaviour increasingly difficult to excuse. We should remember that it was South African mediation in the March elections that made it more difficult for the Mugabe regime to rig the results than in previous contests. And the ANC president, Jacob Zuma, has taken a much more critical line towards Mr Mugabe than the South African President, Thabo Mbeki.

So what now? The Zimbabwean leader's personal defeat in the first round of the election has dimmed his aura of invincibility. No amount of beatings and killings can restore it. As the US Ambassador to Zimbabwe, James McGee, argues, "We are dealing with a desperate regime here that will do anything to stay in power."

Yet, sadly, that does not mean the end is in sight. As we have seen in Burma, desperate regimes can be formidable at clinging to power. And there are reports that the leaders of the Zimbabwean military would not countenance regime change, even if Mr Mugabe would. There is talk of a "junta" now being in control. Mr Mugabe lost his democratic legitimacy as a political leader long ago. But, in another tragic twist for Zimbabwe, it seems his rule as a military-backed "strongman" may have begun.