Can Zimbabwe cure its hangover from Mr. Mugabe?

When a leader dominates a country as long and as disastrously as Robert Mugabe dominated Zimbabwe, his departure is bound to be both exhilarating and traumatic. For 37 years his was the face, staring down the walls of every office, store and bank, of a regime that suppressed and dragged down one of Africa’s most promising nations. Now, at last, he is gone. But the Zimbabweans who danced in the streets of Harare and Bulawayo on Tuesday also knew that the tyrannical system he had created was still alive.

For now, the military leaders who isolated President Mugabe last week and the leaders of ZANU-PF, the party that dominated Zimbabwean politics and pushed him out, were hailed as heroes. But by all indications the soldiers intervened not so much because Mr. Mugabe’s rule had become intolerable – it has been that for a long time – but because his corrupt and unpopular wife, Grace, (whose whereabouts remain unknown) was maneuvering to succeed her failing, 93-year-old husband.

Gen. Constantino Chiwenga, the armed forces chief, took action only after Mr. Mugabe fired Vice President Emmerson Mnangagwa, the successor preferred by the military. Now Mr. Mnangagwa is at the helm of the party and about to be installed as president.

That the transition had at least the semblance of legitimacy is to be welcomed. But it is a stretch to presume that Mr. Mnan- gagwa, or ZANU-PF, or the military – all of whom colluded in Mr. Mugabe’s rapacious rule – will change stripes once in charge. Mr. Mnangagwa was the security head when a North Korean-trained force massacred thousands of civilians in a campaign against the rival Ndebele ethnic group. General Chiwenga was involved in the brutal crackdown after Mr. Mugabe’s loss in the first round of elections in 2008. And ZANU-PF harbors the benefactors of the spoils of misrule.

Arrayed against that is the obvious longing of the Zimbabweans who celebrated on Tuesday for a better day, and the fact that for all the economic and political damage done by Mr. Mugabe, Zimbabwe is still one of the best endowed, best educated and most attractive countries in Africa.

Mr. Mnangagwa could make a new start by lifting some of the more onerous repressive measures, like eliminating the new Ministry of Cyber Security, Threat Detection and Mitigation, which was supposed to monitor online criticism of the government. He could also bring the opposition leader, Morgan Tsvangirai, into the government and could prepare for free and fair elections next year.

To improve the low odds of that happening, the United States, Britain, other Western governments and Zimbabwe’s African neighbors must offer Zimbabwe a financial lifeline, along with an unequivocal demand that the government hold internationally supervised elections next year.