When will our politicians realise that Africa has changed? Aid is dead. Trade is the future.

The dominant headlines out of Africa are as depressing as always in the Western media: a terrifying disease on the rampage, brutal conflict in one basket case of a nation, looming famine in another. But in Washington this week, the president who came to power offering such hope for his father’s continent is finally making attempts to live up to those immense expectations.

For the next three days, Barack Obama is hosting nearly 50 African heads of state at an unprecedented summit. This is partly to prove his commitment to the continent after such a disappointing first term, alongside recognition that those lands lying on the religious fault-line have become the latest focus in the fight against terrorism. But mainly this is an attempt to recalibrate American attitudes by underlining changes taking place at such pace in many of Africa’s 54 nations.

Unlike his predecessors, this son of a Kenyan economist is not posing as a heroic saviour of Africa. Obama tells its leaders with admirable bluntness to stop making excuses for their own failures and talks in optimistic terms of thriving markets, of youthful entrepreneurs, of innovative technologies. “Young Africans are less interested in aid and more interested in how they can create opportunity through business,” he said last week.

His summit is belated acknowledgement of Africa’s rise. The statistics are becoming worn, but need restating given the clichés that cling to the continent in Western discourse. It is home to several of the world’s fastest-growing economies, the youngest population and, taken collectively, has a bigger middle-class than India. Many of its most rapidly expanding nations do not rely on natural resources, with nearly two-thirds of growth last year coming from strong consumer spending. And almost half its citizens now live in cities.

The event is driven by economic imperatives - an attempt to catch up with China, which overtook the US to become Africa’s biggest trading partner in the year Obama moved into the White House. Washington’s policies there have been driven largely by the Pentagon in recent years. The result is China now has nearly 20 times as many commercial attaché across the continent - as well as more than one million of its people who have migrated there to seek their fortunes.

It is Chinese motorcycles and mobile phones - alongside Indian-made medicines, Turkish-built factories and innovative African technologies - that are transforming lives for millions of the planet’s poorest people. Like it or not, capitalism and consumerism drive profound change. Yet too many in the West remain locked in what Ngozi Okonjo-Iweala, Nigeria’s respected finance minister, calls a “lingering perception gap” when it comes to Africa, still fixated on anachronistic aid.

Nowhere is more hooked on these salvation fantasies than Britain. Contrast the Washington event with former foreign secretary William Hague striding in to his recent four-day summit on conflict rape with Angelina Jolie and Brad Pitt. For all its noble intentions, this was the perfect symbol of how our politics has been hijacked by celebrity causes when it comes to global development, with a preference for simplistic slogans and photo opportunities over the complexity of successful policies.

We suffer from a generation of politicians inspired by Live Aid, who love to pontificate about saving the world while chucking away taxpayers’ cash on aid concepts that corrode democracies, fuel conflict and encourage corruption. These flawed ideas are increasingly discredited by academic experts and disliked in recipient nations. Yet the self-serving alliance of a swollen aid industry, struggling media and compassion-seeking politicians push these policies and perpetuate crude stereotypes. They present Africa as a place of hopeless darkness filled with chaos, disease, hunger and poverty - and the legacy of these distorted images means Britain is losing out in the new scramble for African trade.

I recently urged the boss of one of Britain’s fastest-growing technology companies to expand into Africa. “But I would be scared to go there,” he replied instantly, citing violence and corruption as his chief concerns. I had a similar reaction when suggesting to the chief executive of a Premier League team that they tour West Africa. Such attitudes were shown up in an Ernst & Young survey that found firms not present in Africa ranked it the world’s least attractive investment destination; those already here, however, were hugely positive.

Few countries can match our arsenal of soft power, what with the historic links, shared language in many countries, and even that modern phenomenon of Premier League football. Yet Britain’s share of trade with Africa has plummeted in the post-colonial era from more than one-quarter of the total value in 1960 to less than four per cent in recent years - roughly on a par with the Netherlands. Meanwhile to the delight of our competitors, African entrepreneurs are deterred from coming here to discuss deals, network or receive training by a hostile visa and immigration regime.

Ministers love to talk of the global race but, with its blinkered aid fetish and self-harming visa policies, Britain is falling behind the pack when it comes to Africa. We will suffer for it. Now that even the United States is waking up to what is happening in this remarkable, vast and diverse continent, is it too much to hope that our political leaders might do the same?