Mark Malloch Brown, Britain’s secretary of state for Africa, said neighbouring countries shutting their borders would deny Zimbabweans an escape route and exacerbate the health and food crises already afflicting a desperate population.
"Any effort to close off Zimbabwe to the delivery of fuel would undermine the health efforts and the food distribution efforts," Malloch Brown told reporters in London after returning from South Africa, where he discussed Zimbabwe’s situation.
"That border at the moment is a vital escape route."
With up to half Zimbabwe’s estimated 10 million people dependent on food aid — which has to be distributed by trucks — and hospitals short on equipment and supplies as they try to deal with a cholera epidemic, widespread HIV/Aids infections and the threat of malaria, shutting borders would worsen matters.
"It’s not necessarily wrong," he said of the U.S. proposal. "But people want to make sure that any effort like that is hitting the leadership and not just making matters worse for poorer people."
A senior U.S. official said on Thursday that if neighbouring countries sealed their borders, and prevented the flow of remittances from Zimbabwean exiles, it would bring the country to its knees "in a week".
"There is a continued outcry from African nations that this is an African problem and it needs an African solution," said the official, who spoke on condition of anonymity.
"It takes something as simple as closing the borders. Zimbabwe is a land-locked country. The closure of the border, literally in a week would bring this country to its knees.
"There is still a formal economy in Zimbabwe — $2 billion still flows into this country through various means, and even a lot in the informal economy. A lot of that money flows across the borders, illegally or legally, with South Africa."
South Africa and other members of the Southern African Development Community, several of which border Zimbabwe, have been trying to put pressure on Mugabe, urging him to share power and ease the suffering.
But none of the measures taken so far — including withholding aid and financial guarantees — have done anything to shake Mugabe’s grip on power after 28 years.
A senior Western diplomat familiar with the situation in Zimbabwe said on Friday that sealing the borders would only provoke a more rapid exodus of people and higher mortality without loosening the government’s hold on power.
"You would damage people and it would probably not damage the regime," he said. "If you’re going to make it work, you’ve got to get all the neighbours to agree and there’s not sufficient buy-in to make that happen."
Even if the economy completely collapsed, something the diplomat said could happen in the next three months, Mugabe and his close aides would still be able to survive on income from gold and diamond mines, as well as keeping "somewhere between 8 and 10,000 men" in military uniform close at hand.
In terms of suggestions, he said, sealing the borders is "neither a theoretical nor a practical proposition".