By Joseph Winter
South Africa is seen as the key international player in efforts to find a way out of Zimbabwe's political impasse, but in the run-up to parliamentary elections it is coming under increased pressure from all sides.
Does Mr Mbeki (r) want Mr Mugabe (l) to embrace change?
South Africa's President Thabo Mbeki last week shocked Zimbabwe's opposition by saying the elections would be free and fair.
But trade union federation Cosatu, an ally of the ANC government, says it will picket the border, arguing that the elections will be flawed.
Zimbabwe's opposition Movement for Democratic Change (MDC) has long accused Mr Mbeki of being too soft on President Robert Mugabe through his policy of "quiet diplomacy", and has urged him to get tough.
And the Zimbabwe government has not made life easy for South Africa by accusing it of spying.
Three prominent Zimbabweans, including two senior officials of Mr Mugabe's Zanu-PF party, were jailed last month after being convicted of passing intelligence to a South African secret agent.
Last year, US President George W Bush said Mr Mbeki was the "point man" on Zimbabwe, and so his verdict on the elections will be studied closely.
But the MDC says that by declaring the results in advance, Mr Mbeki has lost an opportunity to keep the pressure on Zimbabwe during the election campaign.
Political analyst Brian Raftopoulos from the University of Zimbabwe says that Zimbabwe was always confident that its neighbours would not criticise the conduct of its elections whatever happened - and this was why it felt able to arrest the spies.
Indeed, South African observers gave a clean bill of health to the 2000 and 2002 elections, which most other monitors said were marred by widespread violence and fraud.
South Africa's refusal to publicly criticise Mr Mugabe has often been explained as solidarity stemming from a common struggle against white minority rule.
But Chris Maroleng, from South Africa's Institute of Security Studies, says that is too simplistic, because the ANC and Zanu-PF were never allies during the struggle against colonialism; each backed rival parties in the other country.
"South Africa has had to tread a very careful path around the minefield of being portrayed as a Western puppet by Mugabe," he told the BBC News website.
Some MDC rallies are allowed
South Africa has always believed that its national interest lies in avoiding civil war in Zimbabwe, which would lead to the steady flow of economic refugees across the River Limpopo becoming a political flood.
Mr Maroleng says the Zimbabwean spies belonged to a faction within Zanu-PF, favoured by South Africa, which has recently lost ground in the battle for control of the party.
The newly dominant group, led by retired General Solomon Mujuru, views South Africa with suspicion, he says.
So will the elections be free and fair?
The MDC says that recent changes to comply with new regional electoral guidelines are superficial.
For example, to satisfy the "fair access to state media" clause, the MDC is now allowed to pay enormous fees to air short campaign adverts on state television, while news broadcasts fawn over Zanu-PF rallies and ignore the opposition.
Will Mugabe be happy to take a ceremonial job?
Police continue to turn a blind eye to election violence perpetrated by the ruling party and refuse the opposition permission to hold rallies, the MDC says.
Mr Mugabe has always denied rigging previous elections and says the opposition cries foul to mask its lack of popular support.
On this point, Mr Maroleng agrees with the MDC.
"It is quite clear that Zimbabwe has not adhered to the SADC [Southern African Development Community] protocols."
But he, too, does not expect any public criticism, because of regional realpolitik and a hope that the polls will offer a way forward.
He sees the most likely outcome of the election as being an overwhelming Zanu-PF victory, which "unfortunately" offers the most optimistic scenario for Zimbabwe's future.
This is why South Africa is reluctant to criticise Mr Mugabe's handling of the election.
The Mujuru faction is more pragmatic and moderate than the deposed group led by Parliamentary Speaker Emmerson Mnangagwa, he says.
With a two-thirds majority in parliament, this group would move to change the constitution and create an executive prime minister, with President Mugabe taking a more ceremonial role as "father of the nation".
Taking advantage of this relatively fresh start, this new prime minister might then be able to form a government of national unity with the MDC and change economic policies, attracting a return of donor funding and starting to turn round the economy.
MDC leader Morgan Tsvangirai has twice been charged with treason
An MDC victory, which appears unlikely given the way the rules favour Zanu-PF, would only lead to more of the same, damaging stand-off the country has experienced for the past five years, he says.
An MDC parliament would not be able or willing to work with a Zanu-PF government and the pro-Mugabe army might even be tempted to stage a coup.
Similar scenarios, relying on a moderate Zanu-PF faction, have been painted in the past and have not come to pass on the ground.
South African efforts to set up direct talks between the parties and possibly work together to solve Zimbabwe's economic problems came to naught.
But if Mr Maroleng's predictions do come true, South Africa will be able to feel that its policy of "quiet diplomacy" has been vindicated, whatever the feelings of Zimbabwe's hard-pressed opposition activists.
If not, Zimbabweans will probably have to get used to the idea that their current hardships are likely to last until 2008, when presidential elections are due.
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