Mbeki brokered the power-sharing deal that brought Zimbabwe’s long-time President Robert Mugabe together with his erstwhile rival Morgan Tsvangirai, who became prime minister in a unity government in February.
Under the joint administration, Zimbabwe has halted its spectacular economic collapse, abandoning its worthless currency and easing price controls, which has brought food back on to store shelves.
But with unemployment at 94% and more than half the population surviving on international food aid, the country remains mired in a humanitarian crisis that shows few signs of easing.
Squabbling within the unity government is rife, most dramatically between Finance Minister Tendai Biti, one of Tsvangirai’s top aides, and central bank chief Gideon Gono, who presided over years of world-record hyperinflation.
"South Africa was instrumental in the negotiations for the power sharing government and they will support it" despite the problems, said Joseph Kurebga, a Harare-based political analyst.
But South Africa’s stake in the success of the government goes well beyond diplomacy.
Up to three million Zimbabweans have fled to South Africa in hopes of earning a living, while a cholera epidemic that erupted last year quickly seeped across the border.
Mbeki dealt with challenges though his so-called "quiet diplomacy" that avoided calling out Zimbabwe on its failures. Zuma is unlikely to prove so gentle, analysts said.
"They are going to maintain this idea of constructive engagement with the leadership in Zimbabwe, trying to get them to come together around the table and resolve whatever issue might arise," said Siphamondla Zondi, researcher at the Institute for Global Dialogue.
"But I don’t think that they are going to have patience with the Zimbabwean players should they not move along as expected."
Zuma has proven himself a capable negotiator, credited with curbing political attacks between the African National Congress (ANC) and the Inkatha Freedom Party in the 1990s.
As the crisis unfolded in Zimbabwe last year, Zuma didn’t hesitate to speak out, saying that he believed Zimbabweans were demanding change and that delays in the violence-plagued elections were "unacceptable".
"What we saw from Mr Mbeki was a kind of silence about the violence in Zimbabwe," said Isabella Matambanadzo, Zimbabwe programme director for the Open Society Initiative for Southern Africa.
"Zuma is a very smart political animal," she said.
"He may have a few surprises in store in terms of the leadership style he’s going to establish in the region, and in particular in trying to build a leadership style that is credible to the people of the region."
But with the unity deal already in place, Zimbabwe is unlikely to dominate Zuma’s concerns when he is faced with a sagging economy and pressing demands to save jobs and fight poverty at home, analysts said.
Takavafira Zhou, a political scientist at Zimbabwe’s Masvingo State University, said domestic affairs would demand more of Zuma’s attention than the affairs of neighbours.
"Zuma has enough problems on his hands to embark on a robust foreign policy," Zhou said.
Warning as Tsvangirai says government is ‘broke’
State schools in Zimbabwe have been ordered to slash their fees in a bid to stave off the collapse of the country’s education system.
The move came after Tsvangirai admitted that the unity government was "broke" and could not meet union demands for higher wages.
Zimbabwe’s Sunday Mail said David Coltart, the Education Minister, had recommended that state schools should cut their fees when they open for a new term on Tuesday because many parents could not afford them.
"I cannot divulge the figures at the moment because the recommendations are going to Mugabe, Tsvangirai and deputy prime minister Arthur Mutambara on Monday," he was quoted as saying. "However, what we want are substantial cuts."
The government set school fees in state schools at between $20 and $280 a term two months ago, but many parents have failed to pay, citing low wages and high living costs.
Coltart added: "When the fees were set in March, the assumption was that we would get balance of payments support [to] kickstart the economy. But this has not materialised and parents are worse off than before."
The malaise in Zimbabwe’s education system, once the envy of Africa, is a telling measure of the country’s steep decline. In the early years of independence under Mugabe, who began his career as a teacher, 96% of children attended school.
Mugabe has since presided over an exodus of tens of thousands of teachers, which has left many schools shut and fears that a generation will grow up without education. Zimbabwe was criticised last week by Amnesty International for failing to protect teachers from harassment and beatings during last year’s elections.
The country’s top university in Harare has been closed for nearly a year, with broken toilets and no piped water. The state media reported on Sundaythat only 68 students out of 12 000 had paid their full fees of about $300 when the college tried to reopen in March, and it was now appealing for foreign assistance.
Zimbabwe said last week that it had secured $400-million in credit lines from African states to revive some of its ailing industries, many of which are operating at below 20% of their capacity.
Trade unions have called for a monthly minimum wage of $450 and threatened to go on strike if their demands are not met. But Tsvangirai told a May Day rally in Harare that no state worker, including Mugabe, was earning more than $100 a month.
"This government is broke, and we are only able to pay the $100 allowance," he said, adding that this would "graduate into a proper salary" when the situation improved and more people were paying tax.
"We have been in office for less than three months. I plead with you to please give us time." – AFP,