Robert I. Rotberg writes:

President Robert Gabriel Mugabe is Zimbabwe’s curse. In his three decades in power, Mugabe has traded the country’s economic promise for withering decline. He’s turned what was once the breadbasket of the region into a deathtrap for its own citizens. He has crushed the opposition, cleared slums with bulldozers, ignored a devastating cholera outbreak, and chased millions of desperate migrants over the border into South Africa. His passing, when it comes, may seem like a blessing.

Yet when the ailing, 86-year-old Mugabe inevitably leaves office, by fair means or foul, more trouble is in store for the nation that he has singlehandedly destroyed. And hardly anyone is fully prepared for that game-changing moment — not Zimbabwe’s opposition; not neighboring South Africa; not Western embassies or regional multilateral organizations. No one has a workable contingency plan. And with everyone likely to be caught flat-footed by Mugabe’s demise, the president’s cronies are likely to attempt to seize power and install a regime as bad as or worse than the one left behind.

For now, Mugabe is keeping a tight grip on the Zimbabwean state. After losing a presidential election in 2008, he agreed — under heavy international pressure — to share power with the vote winner, opposition leader Morgan Tsvangirai, and the two adversaries were forced into an unhappy marriage in 2009. Although Tsvangirai was made the prime minister, Mugabe continues to run the country according to his own whims. Defying the 2009 agreement, he appoints provincial governors, judges, ambassadors, an attorney general, a central bank governor, and military generals without so much as a nod in Tsvangirai’s direction. In fact, he ignores Tsvangirai most of the time, and blames the prime minister for Zimbabwe’s ongoing economic and social failings.