If you have a sense of humour and any experience of African politics over the last 30 years surely you can’t have missed the irony of former Zambian Premier Kenneth Kaunda being sent to persuade Robert Mugabe to step down.

In a nutshell, two 93-year-olds, who both long overstayed their welcome and were old enough to know better; actually having to debate doing the right thing.

The day leaders in Africa realise that clinging onto power merely ends in tears, court cases and the ignominy of being despised by you own people – the better.

Now, don’t get me wrong, I think Kaunda is a lovely old soul. I sat in his lounge 20-odd years ago interviewing him about his political comeback and spent months covering his treason trial in Lusaka. We were threatened and abused by the military and police in a trial that looked more like an army camp than a High Court.  In prison, Kaunda grew a massive, bushy, white beard in protest and when he was acquitted I asked him – on camera – why he had ended up looking like Father Christmas.

“Chris, is that not a noble person to be?” chuckled Kaunda. We had that kind of relationship.

True Kaunda has a claim to being a statesman and is probably one of the more benign leaders of Africa.   But I still don’t understand why Kaunda stayed in power for 27 years. It took the burning of Lusaka by angry voters to make it happen – at least, he tried to do the decent thing by going to the polls in 1991 where he lost and was unceremoniously kicked out. I was told by a daughter of a minister in Lusaka that on the night of the election defeat the families of the new ministers knocked on the doors of the old to throw them and their furniture onto the street.

Instead of peaceful retirement on a cattle post – like the revered Ketumile Masire of Botswana – Kaunda was vilified on the streets and pushed about by the authorities. They tried to deport him claiming he wasn’t a Zambian because he was born in neighbouring Malawi; all in all, the wrath of the people who remembered the food shortages and indifference of their leader’s era.

As for Mugabe, should a man of his intellect really be told at the age of 93 that enough is enough? Surely a divine right to rule for life should be a relic of the past like the royal families of the world who cling onto it. For the last few decades Mugabe’s occupation of the top spot has stifled new ideas and stagnated the natural race for succession among the young and bright who grew up in a free Zimbabwe. Woe betide those who stood in his way.

Worried about prosecution? Mugabe should be and I am sure he is negotiating for immunity from being dragged through the courts.  If he gets it will be a sad day for governance in Africa, it will send out a message that you can ill-treat your people with impunity.

Just imagine how Mugabe could have been regarded if he had stepped down in 1990 after two terms. He would have been revered as the scholarly gentleman who led Zimbabwe out of colonialism to freedom. The man who left one of the jewels of Africa, prosperous educated and free. The world would have beaten a path to his door to receive counsel. He would have been invited to conferences all over the world. There would have been lectures and universities in his name.

Instead Mugabe will face the indignity of being dragged from power before a jeering mob. His legacy as soiled as baby’s nappy:  wasn’t it Mark Twain who said that “Politicians and diapers must be changed often, and for the same reason”?