Yet South African President Thabo Mbeki continues to make excuses for Mr. Mugabe  who is more brutal than Ian Smith ever was  out of misplaced deference for a common history in the liberation struggle. Zimbabweans suffered so much for so many decades from white racism that the last thing they need is excuses for Mr. Mugabe’s brutality because of his skin color.

Life expectancy in Zimbabwe has already dropped from the low 60s to the high 30s. It’s true that he has created more trillionaires than any other country, but that’s only because inflation may be as much as 10 million percent. Anyone with $90 is a trillionaire in Zimbabwean dollars, and buying a small loaf of bread costs one billion Zimbabwean dollars.

When I grew up in the 1970s, a central truth was that Ian Smith was evil and Mr. Mugabe heroic. So it was jolting on my last visit to Zimbabwe, in 2005, to see how many Zimbabweans looked back on oppressive white rule with nostalgia. They offered a refrain: “Back then, at least parents could feed their children.”

Africa’s rulers often complain, with justice, that the West’s perceptions of the continent are disproportionately shaped by buffoons and tyrants rather than by the increasing number of democratically elected presidents presiding over 6 percent growth rates. But as long as African presidents mollycoddle Mr. Mugabe, they are branding Africa with his image.

Image Nicholas D. Kristof Credit... Fred R. Conrad/The New York Times

To his credit, Zambian President Levy Mwanawasa has taken the lead in denouncing Mr. Mugabe’s abuses, and Nelson Mandela bluntly deplored Mr. Mugabe’s “tragic failure of leadership.” Mr. Mandela could also have been talking about Mr. Mbeki’s own failures.