For what it’s worth I think David Cameron is right. No, I haven’t taken leave of my senses. I am however in agreement with the Prime Minister’s observation that Nigeria and Afghanistan are “fantastically corrupt”.

Already I sense a fusillade of political brickbats being readied for hurling in my direction. So, before those inclined to launch them take aim let me explain where I’m coming from and the various caveats I attach to my unanimity with the PM.

First, there is simply no denying that both Nigeria and Afghanistan are plagued with corruption. Their respective positions on Transparency International’s global Corruption Perceptions Index that puts both near the bottom of the list, tells us all we need to know.

Both countries' leaders have acknowledged as much over the past few days, albeit with their own caveat that others – Mr Cameron – in glass houses should be wary of chucking criticisms around.

Curiously enough, while looking across the corruption index list yesterday, I found that out of the 50 bottom placed countries, I have visited more than half, including Somalia placed last out of the 167 rankings.

During those travels I have had more than enough direct experience of how corruption flourishes and seen the devastating impact it has on the wellbeing and dignity of countless innocent citizens – but more on that in a moment.

The second point I want to make clear is that despite the accuracy of Mr Cameron’s description of Nigeria and Afghanistan, my colleague Iain Macwhirter hit the nail on the head in these very pages this week, flagging up the crass hypocrisy of the UK’s position.

Put quite simply this country’s role has made it part of the problem not the solution to corruption in such countries.

These two points off my chest let me focus then on what I think is equally important in the debate over corruption.

This issue, it’s worth remembering is a global one that ignites passion and anger like few others. Just look at yesterday’s vote to impeach and suspend Brazil's President Dilma Rousseff over accusations she illegally manipulated finances.

Given such outrage, perhaps its not surprising then that commentators have tended to dwell on knee-jerk reactions apportioning heated opprobrium rather than casting light on the complexities and impact corruption has on the developing world.

“The gangrene of a people,” Pope Francis has called it, while US Secretary of State John Kerry sees it as a “radicaliser,” because of its pernicious ability to “destroy faith in legitimate authority”.

Like Mr Cameron, both men are also correct, even if they too leave themselves open to rightful accusations of hypocrisy.

Corruption itself has probably existed since the dawn of human civilisation. It has certainly been around as long as the governments and institutions Mr Kerry and Pope Francis represent.

It’s hard to see how their remarks alone no matter how well intentioned can help those who disproportionately shoulder the costs of corruption.

Across the globe I have witnessed how its corrosive cancer seriously hinders poverty alleviation in developing countries.

In Democratic Republic of Congo for example I recall talking to some young indentured labourers, who worked endlessly for a pittance in dangerous old crumbling gold mines from the Belgian colonial era. All the enormous profits went to warlords and elites who tucked them safely away overseas.

Recently in the sprawling Nigerian city of Lagos, I met a young girl called Elizabeth who would rub menthol on her eyes to make tears in the hope that more people would take pity on her, making the begging that was her only source of income more successful.

Elizabeth lives in an oil rich country that in part accounts for its 15,700 millionaires and handful of billionaires, 60 per cent of whom live in Lagos. Not all of these people are corrupt of course, but many are.

Such corruption cripples prospects for development. How can it not when public-procurement fraud is rampant, or royalties for natural resources are stolen at source, or the private sector is monopolised by a narrow network of cronies preventing populations from realising their potential.

When I speak of Lagos, though, let me be clear that its corruption is no more unique than that in the City of London. All such metropolises have long nurtured a corrupt, mercenary cabal only marginally inconvenienced by the squalor and poverty surrounding them.

Which brings us to the tricky question of how to tackle corruption. The problem here is that there is no one-size-fits-all solution especially in the developing world.

It’s all very well to talk of a “zero tolerance” approach to corruption in international development. An ideal it might be, but an effective strategy must first acknowledge that it is a social and political problem, rather than purely a moral one.

According to one World Bank study if developing countries could control corruption and the rules of law were properly enforced, per capita income could increase as much as fourfold over the long-term.

In his past address to the African Union, US President Barack Obama made the point that “nothing will unlock Africa’s economic potential more than ending the cancer of corruption”. That same mantra is applicable almost anywhere.

There are risks too in some cases of course. For arguably in some instances corruption cannot be wiped out without inevitable collateral damage.

I’m thinking here of places like Afghanistan, Pakistan and Somalia to name just a few where violence is an ever-present threat. In such places corrupt patron-client networks are often the sole source of security and safety.

Backhanders, deals and the selective allocation of assets and wealth

between local elites, service providers and rebel or insurgent groups are sometimes the only way forward.

This is far from ideal of course and often the reverse is true given corruption has another, less-recognised impact. For the fact remains that anywhere citizens watch their leaders enrich themselves at the expense of the population it can become volatile and lead to civil unrest.

Look around the world today and it’s obvious many major conflicts started this way. Was it not the high-handed behaviour of a corrupt police officer and anger towards him that acted as the trigger helping a young Tunisian fruit seller to set himself on fire in 2010, touching off the Arab Spring revolutions? Even today the world is still reaping that whirlwind and will for some time to come.

In places like Nigeria, Afghanistan and Syria where extremist groups like Boko Haram the Taliban and Islamic State (IS) thrive, they do so in part because government officials or leaders have often flaunted the profits of their corruption driving ordinary people into the insurgent’s ranks.

By its very covert nature, the magnitude and extent of global corruption is difficult to estimate. But if World Bank research is anything to go by annual global bribery alone now exceeds $1,000 billion, and the World Economic Forum says corruption costs now exceed 5 per cent of the global GDP.

This is a staggering sum by any standards, and all the while the poor carry the burden.