Former President Bill Clinton in a tête-à-tête with Komla DumorI have interviewed many people while working for the BBC. The standard operating procedure is as follows: study the issues, know the subject, interrogate the guest, hope for a compelling and revealing conversation.

Time is not always your friend. I managed to squeeze 12 minutes out of former British PM, Tony Blair; I had eight minutes with Former UN Secretary-General Kofi Annan; most times in the studio you get just three minutes.

I met Bill Clinton in Zanzibar on his latest tour of Africa. His Clinton Foundation, established after his presidency, raises hundreds of millions of dollars for development projects across the continent. The interview took place in a small open park near the Indian Ocean.

Clinton’s people had generously offered 20 minutes. I would talk to him about a range of issues; his work in Africa, America's influence on the continent, China's emergence as a major player. I really wanted to ask him about Rwanda. The genocide there happened during his reign, close to 20 years ago.

Around 4p.m. and without much fanfare, the 42nd President of the United States walked across the street from a hotel where he'd been having lunch. Under the watchful eye of his Secret Service detail, he strolled up to me and shook my hand.

Clinton is a tall man, 6ft 2" (1.88m). He carries much less weight than during his presidency. He is now a vegetarian and has had some well-publicised health issues. But his sharpness of mind was immediately evident. We stood there for a moment, sizing each other up. He held me by the hand and started speaking.

In 2010, Ghana beat the USA in a football match at the World Cup in South Africa. Clinton was there. He remembered the game. He talked about players and moments that I had long forgotten. He wasn't happy with the outcome but conceded:

“You guys deserved to win."

More small talk. Again about Ghana and his first trip to Africa in 1998; March 23, 1998. Over half a million people gathered at the Independence Square to see him.

This was unprecedented. A moment he said he still relished. As we took our seats, Clinton started explaining his childhood fascination with Africa.

"I was fascinated, like most children, by the wild animals and now my wife and daughter are trying to stop elephant poaching. But I was also always troubled by colonialism. I was troubled by the challenges in the aftermath of it. Then when I was a college student I decided I wanted to go to the Ngoro Ngoro Crater and climb Mount Kilimanjaro. I remember, from the time I was very young I've always been interested."

I asked him if he feels more connected to working with communities in Africa because of his own modest start in life.

He said, “You’ve got to understand. First of all, my public life started in the second poorest state in America, as Arkansas was then. More than half the people lived in communities of less than 2,500 people. Microcredit, microsavings, strategies, better agriculture strategies. I've cut my teeth doing that work as a young man. I do care about it; I think the purpose of politics is to enable people to live better lives. I love this stuff.”

So what about President Obama's record in Africa? The current occupant of the oval office has been criticised for what some call an incoherent Africa policy. Will Obama leave a lasting legacy for the continent like George Bush's President's Emergency Plan for AIDS Relief (PEPFAR) or Bill Clinton's African Growth and Opportunity Act (AGOA)?

“I think he does have a good legacy”, says Mr Clinton, “but I do think when he took office, our economy’s wheels were coming off. He had to wind down a war in Iraq. Then he had to deal with how to bring down the conflict in Afghanistan. He's had one or two other things to do. But I do think that he cares about Africa and I'll be surprised if he doesn't spend quite a bit of time on it in his last three years.”

I was now ready to get into the substantive issues, like China usurping America as the pre-eminent power in Africa. According to research conducted by the Financial Times, the China Development Bank and the China Export Import Bank offered loans of at least $110 billion to governments and firms in developing countries in 2009 and 2010, more than the World Bank did. I asked, “is America playing catch up”?

“On everything but healthcare, if you look at it what America invests, both in the public funds like PEPFAR and USAID and in the investments made by the Gates Foundation, and the work that we do here, what the United States does in trying to build infrastructure for healthcare dwarfs what everybody else does, I don't believe we spend enough money on basic economic growth initiatives. So I won't argue that the Chinese are going to get a lot of goodwill. I don't necessarily think it's a bad thing for America if African countries appreciate both what we try to do to help their kids stay alive and what the Chinese do to give them better infrastructure. And I think that we've got to try to create a future that we can share with the Chinese; not one where everything is a zero sum game.”

The clock was ticking and I could see Mr Clinton's handlers out of the corner of my eye - 20 minutes goes quickly.

I moved on to human rights and his bold support for Rwanda and its President, Paul Kagame.

The Kagame government has been accused by the UN of backing rebel groups in the Democratic Republic of Congo. Rebels responsible for some of the violence and atrocities we have reported on for my programme, Focus on Africa. The Rwandan government has denied these claims. Among Rwanda's strongest defenders is Bill Clinton:

“Well first of all... the matter has not been fully litigated,” says Mr. Clinton.

“Secondly it's complicated by the fact that the section of Congo near Rwanda is full of people who perpetrated the genocide, who spurned the president's offer to come home and not go to prison and you can't get around the fact that the economic and social gains in Rwanda have been nothing short of astonishing, under Kagame, and he says he's gonna leave when his time's up. So I understand that there are some people in the human rights community who believe that every good thing that has happened in Rwanda should be negated by what they allege that they have done in the eastern Congo.”

I challenged him. Was this spirited defence driven by the guilt of failing to intervene on behalf of the hundreds of thousands who were murdered and raped in 1994 when he was President?

He paused…

“No, not guilt because, whatever guilt I had went away when I took responsibility for not helping them. I remember in 2001 when I went back to Rwanda for the second time, a reporter was riding in the streets of Kigali with a taxi driver and he asked ‘aren't you mad that Bill Clinton's here working on aid and all this stuff’? He said, ‘no I'm not’. And the reporter asked, why? And he said, ‘First, he didn't make us kill each other; we were all adults and we did it. And we've got to stop blaming outsiders for what we did to ourselves; that's Kagame's contribution’. And then he said, ‘secondly, at least he said I'm sorry - nobody else has apologised’.”

“No, I don't think it is guilt. But I suppose I do make more allowances for a government that has produced as much progress as that one has - and has been well organised and otherwise had the rule of law, and so that's the way it is. There are very few situations that are perfect.”

It was over. At least officially. We got up and we started to stroll along the promenade. He spoke about agriculture and empowering farmers. As we walked and the more he spoke, I began to get the impression that he is happy with what he is doing now; happy trying to find solutions to what he thinks are the world’s problems.

“What if”, I asked, “there was another race for the White House in 2016?” He laughed.

“If I knew the answer I wouldn't tell you! Happily I can be honest, I don't know. I'm for whatever my wife wants to do. I didn't know if I had one more race left in me the last time, but I thought the president was getting a raw deal and I was glad to try to help him. But whatever happens there, I'm going to keep doing this.

This is what my job is. I love this job, I love doing this foundation work.”

It was time to say goodbye. I thanked him and he walked to the crowd of people who gathered to watch us. I heard him greeting the bystanders. We had been talking for close to an hour. Good job done.

By Komla Dumor/Daily Graphic/Ghana The writer is a journalist with the BBC