Three weeks ago Thabo Mbeki, the South African President, flew to Gleneagles and signed a pledge with the world’s richest nations to foster good governance in Africa in return for an historic increase in aid to its poorest countries. He is now preparing a big financial bailout of his own — for Zimbabwe, where government-sponsored thugs continue to terrorise those suspected of supporting President Robert Mugabe’s opponent in this spring’s elections, and bulldozers continue to flatten their homes.

Mr Mbeki’s public rationale is one of engagement. “We don’t want Zimbabwe collapsing next door,” he said recently. He also, rightly, expressed concern for “the broad interests of all Zimbabweans”, as distinct from those of the venal clique that has prospered so indefensibly during Mr Mugabe’s 26 years in power. Mr Mbeki’s anxiety is warranted: no economy exports crime, dependency and chaos more efficiently than an imploding one. But even South Africa, acting on its own, can do little to prevent the implosion. While officials in Pretoria are hoping to shoulder Zimbabwean debt worth $300 million, their counterparts in Harare say they need $1 billion for emergency food and energy imports alone. The help that Mr Mbeki can offer pales beside the $50 billion package hammered out at the G8 summit, even allowing for delays in delivery and the competing demands of the rest of the continent. The only obstacle to Zimbabwe ’s inclusion on the list of G8 beneficiaries is Mr Mugabe himself, and Mr Mbeki’s vaunted “quiet diplomacy” towards Zimbabwe, far from helping ordinary Zimbabweans by easing their tyrant out of power, is prolonging their agony by helping him. It is short-sighted appeasement, and against the spirit of everything Mr Mbeki endorsed at Gleneagles. If he wants to keep the regional leadership role he enjoyed there, it must stop.

Mr Mugabe does not seem to have been chastened by his international pariah status. He promised a free and fair election but delivered systematic intimidation of his brave opponents in the Movement for Democratic Change. He hinted that his campaigns of forced relocation might relax, but “Operation Drive Out Trash” continues unabated. A report by the UN last week estimated that this egregious punishment of suspected MDC supporters has left 700,000 homeless so far. About 20,000 more lived in slum dwellings destroyed in the past few days, and riot police have been beating those refusing to leave.

The IMF must decide this month whether or not to expel Zimbabwe from its club of eligible borrowers. It should do so rather than let Mr Mugabe claim to have called its bluff. Unfortunately he has already found an alternative source of aid in China. Beijing, which will do deals with anyone, is using Zimbabwe to trumpet its own axiom of non-interference in other countries’ internal affairs. For Zimbabwe’s neighbours and traditional partners this is not an option. They should, indeed, “ engage”, but with the moderates who must shape the future of this misruled country.