The next three weeks in Zimbabwe will be the most traumatic in its history. Robert Mugabe has declared war on the Movement for Democratic Change (MDC), NGOs and churches to reverse the electoral defeat he suffered in March. It is a war on unarmed people. Can he win it and what would victory mean?

Scenario one: When the votes are counted after a peaceful, well-organised and credible election on June 27, President Mugabe concedes defeat, congratulates Morgan Tsvangirai, hands over the reins of power and retires. Likelihood? Zero.

The official results of the election on March 29 did not give Mr Tsvangirai more than half the votes so there must be a run-off. To secure victory, Emerson Mnangagwa, one of the architects of the massacres in Matabeland in 1983, with the heads of the police, defence forces and Gideon Gono, the Finance Minister, has launched a violent nationwide campaign to destroy the opposition's capacity to deliver the vote.

Only the towns that the ruling party now believe they cannot win have been spared. Key MDC organisers have been abducted and killed. The death toll is about 50 so far but may be many more. Anyone suspected of voting MDC is seized and ritually beaten, often on the back, buttocks and legs with whips and sticks, sometimes wrapped in barbed wire.

Another strategy is to force people out of their homes by burning their houses. Driven from their constituency areas, they will be disqualified from voting. MDC leaders are detained. NGOs are ordered to stop work in rural areas so that news of what is happening there cannot reach the outside world. It also means that hundreds of thousands of people, now dependent on food aid, will not be fed. The last strategy is to prepare a massive rigging campaign. Professionals such as teachers, who acted as election officers in the first round, are being intimidated so that Zanu (PF) officials can step in to run the polling.

Opinions vary on whether all this will succeed in cowing the people or if it will make Zimbabweans more determined to cast their votes for the MDC. But even if Mr Tsvangirai were to win the most votes, it is inconceivable that, in its present mood, the regime would concede defeat.

Mr Mugabe believes he won Zimbabwe by conquest, through the liberation war. Zimbabwe was never a one-party state, but to him the function of elections is to confirm his possession. The idea that he could be deposed through the ballot box is unthinkable. His wife has vowed publicly that Morgan Tsvangirai, the MDC leader, will never see the inside of State House. To justify his claim - and his war - Mr Mugabe has created a fantasy enemy: Britain. He says the British want to recolonise Zimbabwe, bring back the white farmers and re-create Rhodesia again. MDC is their creation and puppet.

While the key player outside Zimbabwe, President Thabo Mbeki of South Africa, remains silent on these developments, his probable successor, Jacob Zuma, says they have undermined any possibility of a credible election. He recommends a government of national unity.

This is scenario two: a powersharing agreement between both parties. Likelihood? Minus zero. Neither side wants this election but the possibility of a Kenya-style government of national unity is unthinkable.

Kenya had a lot to lose from political disruption. Zimbabwe has lost it all already. About ten powerful allies of Mugabe do have a lot to lose, which is why they hold on to power at any cost. They could offer the MDC a few places in government, but the MDC would not accept them. The only terms under which MDC would enter a reconciliation government - as they prefer to call it - is if they headed it.

Which brings us to the third scenario: a victory for Robert Mugabe. Likelihood? High. The party was complacent in the first round. It assumed the rural areas would vote Zanu (PF) but they didn't. This time voters in traditionally loyal areas will be urged, even forced, to the polling stations. That, the campaign against the MDC and rigging might well reverse the result.

This scenario raises three more fundamental issues: the splits in Zanu (PF), the reaction of the region and the economy. Everyone knows a Mugabe victory will not reverse Zimbabwe's catastrophic disintegration - although there are some who say he is willing to step down but will not be driven from office.

After the declaration of war on MDC, there is no one in the senior hierarchy of Zanu (PF) who would be an acceptable replacement except as a stopgap. The party itself is deeply riven by factions.

If Mr Mugabe wins, the reaction of the regional leaders would be crucial. But since Mr Mbeki's quiet diplomacy has failed, he appears to have no other policy. The other presidents of Southern Africa are divided. They will not condemn Mr Mugabe but would probably not continue to support him if he wins an election under current circumstances.

The economy can no longer provide the Government with the revenues it needs to keep it in power. No one will lend it money. Every source of wealth has been raided and drained. Inflation is now more than

2 million per cent. African economies do not die, they sink into subsistence, but the Government's ability to pay soldiers, policemen, party officials and civil servants is at an end. The election itself will drain the last few drops of wealth from the coffers.

These factors create fourth and fifth scenarios.

Scenario four: The unpaid Armed Forces and police could break up into pro and anti-Mugabe factions within the party. Some may support the MDC. As the Armed Forces disintegrate, warlords take over local areas. Zimbabwe begins to look more like Somalia. Likelihood? Possible.

Scenario five. The miracle. Some random factor not in the equation at the moment suddenly turns history. Maybe the death or defection of a key Mugabe ally: Mr Gono, the Finance Minister, for example, who has been churning out increasingly worthless banknotes. Now he is of no further use, but, rich and ambitious, he may not see a future with Mr Mugabe. His defection breaches the wall of the fantasy castle and reality crashes in. Mr Mugabe and his chief lieutenants seek refuge in Equatorial Guinea and a government of national unity is set up.

Likelihood? Impossible to say. But Southern Africa has been known to produce miracles before.

Richard Dowden is director of the Royal African Society. His book Africa: Altered States, Ordinary Miracles is published in September.

Times Recommends

• Fundamentalist brew: faith and power
• Big guns wheeled out for the marginals
• Wanted: new merchants of light