A FEW years ago, just after I'd come back from a visit to Malawi, I was talking to a South African woman in Glasgow.

We were discussing the aid work being done in Malawi when she said something I've never forgotten. Why, she asked flatly, did Westerners insist on meddling in such a dirt-poor country? Wouldn't it be more honest to leave them to their own devices? Weren't we simply raising false hope?

My reply was along the lines of ... well, don't we have a moral duty to help others? How can anyone sit back and watch so many lives being squandered and left unfulfilled? I remembered what I'd seen in Malawi: the heat, the dust, the endless greenery, the modern buildings in Lilongwe and Blantyre, the remote rural villages that seemed to date from 200 years ago; the friendliness of the people, the children's avid curiosity.

Overseas aid is never far from the political agenda. An opinion poll suggests that seven in 10 of us think Britain spends too much on international aid. Ukip's rise has panicked some Tory MPs into arguing inter alia that such funds should no longer be ring-fenced. Enter Tony Blair, and good for him – defending our spending on international aid, and reminding us that the 2005 Gleneagles G8 summit was a success. Its positive legacy is still echoing across Africa, he argues. The proportion of Africans living in extreme poverty is down by nearly 10%. Many fewer children now die before their fifth birthday. UK aid alone has helped five million more children attend primary school. Effective governance and economic growth were prioritised at the time, too, with notable success.

The picture is complicated, of course. Zambian economist Dambisa Moyo has argued that development assistance is a cause of Africa's persistent poverty. And it's unclear as to how many of the successes can be attributed to Gleneagles. Bob Geldof, however, insists that the cancelling of African debt and the doubling of aid in 2005 sparked an "intellectual stampede": the continent now has the world's fastest-growing middle-class and seven of the world's 10 fastest-growing economies.

Foreign investment is booming. War, famine and dictators have become rarer, to quote an Economist survey. Yes, vast poverty remains. But a considerable start has been made. Aid – your money and mine – played a part in that.