What seemed unimaginable has happened. After an uninterrupted 'reign' of 37 years, Robert Mugabe, the de facto emperor of Zimbabwe, has resigned from office. There is genuine jubilation, especially among those who have been at the receiving end of Mugabe's increasingly despotic, corrupt and dysfunctional rule – the majority of Zimbabweans. There is hope that the chains of serfdom are being broken and that we are at the dawn of a compassionate, fairer, humane and democratic Second Republic of Zimbabwe. At the same time, there are factors that counsel us not to throw caution aside even as we are hopeful for change. Why is this?

To begin with, regardless of the gains Mugabe's departure may bring to the long-suffering people of Zimbabwe, we ought to have grave misgivings about the manner in which he left office. He did not leave voluntarily but was deposed by a coup. But was a coup necessary, even in its soft sense? Sometimes we are able to find a just cause for a coup even if we absolutely detest it as a means of effecting political change. On this occasion, however, the coup was a political machination by an army steeped in party politics. What was foremost in the minds of the architects of the coup was not saving Zimbabweans from dictatorial rule but 'getting their man in' before Mugabe's ambitious wife could ascend to the throne, as seemed probable. It is internecine political warfare of the lowest order. The coup was used to settle an internal battle within ZANU-PF, the ruling party. This party, which is indistinguishable from the state, has exercised monopoly over state power and, indeed, violence since 1980 when Zimbabweans liberated themselves from white minority rule. Upon losing to one faction, the losing ZANU-PF faction played its trump card: a pre-planned military takeover. The military intervention, described by the Zimbabwe Defence Force as 'operation restore legacy', has in fact been an operation to restore an ousted ZANU-PF apparatchik – former Vice-President Emmerson Mnangagwa – who has since taken over as president.

Thus, the country's army has been used by a factional wing within ZANU-PF to commit patricide, the slaying of a father for political inheritance but camouflaged in the clothes of a coup which is not quite a coup. The army made some arrests during 'operation restore legacy'; however, it is not clear how many arrests were made or why only certain people were arrested. Moreover, we do not know the exact grounds for the arrests or the legal order that sanctioned them.

In short, there is no indication that due process has been followed. If anything, it seems the arrests have been highly selective and motivated by factional, intra-party politics. This appearance of unconstitutionality bodes ill for democracy in Zimbabwe. Let us hope that the country's courts will not be used to rubberstamp the military intervention.

The protagonists of the coup – the military command and Mnangagwa (now president) – should perturb anyone dreaming of a democratic Zimbabwe. Collectively, Mugabe, Mnangagwa and the military command bear responsibility for the worst atrocities in the post-independence period. It was Mnangagwa who, as Director of CIO (the country's intelligence bureau), supplied the army with the 'intelligence' which facilitated the ruthless and murderous Gukurahundi project in Matebeleland. It was Mnangagwa who, in collaboration with military command, made it possible in 2008 for Mugabe to 'win' an election through the worst state-sponsored election violence independent Zimbabwe has ever experienced. Murder, maiming, rape, and disappearances where committed to secure a win for the ruling party. To date, there has not been accountability for these crimes.

Effective political change must surely begin with diagnosing and candidly facing up to what Zimbabwe's problem is. Put simply, the problem is the capture of a newly independent state by an avaricious nationalist elite and the failure of authoritarian nationalist rule (as opposed to governance) to address poverty, inequality and social injustice. The question is: How does the replacement of Mugabe with someone cut from the very same undemocratic cloth help the nation? Simply removing one emperor and replacing him with a member of his political family does not reassure us that the democratic change Zimbabweans are looking for has come.

This military intervention has been about who gets premier access to state resources, and not about coming to the rescue of the nation. The era of progressive governance is yet to come. It must be secured through the ballot box and only if ZANU-PF's praetorian guard – comprised of intelligence services, the police and, above all, the army – can allow Zimbabweans to exercise free choice. Clearly, Mnangagwa does not have a reputation for respecting democracy. He must prove us wrong and show us, in deeds and not vacuous utterances, that he has experienced a Damascene moment. In any event, it would be a tragedy if opposition parties in Zimbabwe were unwittingly pulled into a sham 'government of national unity'. That would only serve to revive the fortunes of a ruling party which is fratricidal and deserves to perish. ZANU-PF has been incorrigibly corrupt, arrogant and dictatorial in the extreme. In peacetime, it is the ballot box which should play midwife to a democratic Second Republic and not the army.

It is important to remember that Mugabe has left office at the very tail end of his long rule, when corruption has taken hold in virtually all sectors of the state, including the education sector, which saw the University of Zimbabwe award a doctorate to Mrs Mugabe under the most questionable circumstances. Let us put our trust in democratic politics to address the rot and remove it from the Zimbabwean political landscape. We do not need a partisan army or any form of violence to do this for us.

Charles Ngwena is a Professor in the Centre for Human Rights at the University of Pretoria and Head of the Unit on Race and Common Citizenship. He is the author of a forthcoming book: What is Africanness (to me)? Contesting nativism in race, culture and sexualities.

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of the University of Pretoria.