Africa has been treated quite badly by the world powers over the years, though:
Zambia: "USA, can I borrow $2bn to buy some corn from Malawi?"
USA: "I've got a better idea! You borrow $8bn from us! You can buy corn from us for 6 of them, and some of our outdated weaponry for the remaining 2bn"
Zambia: "But why? I only need $2bn! Malawian corn is so much cheaper!"
USA: "We give you both the money and the corn. And some nice weapons too! Everybody wins."
Zambia is then $8bn in debt, Malawi can't sell its corn, and lots of weapons are floating around. The USA have now sold away corn and guns for $8bn, and they will still get $8bn from Zambia from the loan, plus interest.
Not saying it's just an American thing - the Norwegian government did exactly the same with some old rusty ships in the nineties. And I bet there are loads more examples if you just look long enough.
Never mind that the African "countries" were never national states. The Europeans just divided the land between them, and all the people within the borders then had to cooperate to get things going after gaining independence. By that time, they were hopelessly behind the rest of the world in terms of industry, infrastructure and whatnot, while foreign companies already had the rights to extract and export most of the natural resources in the country. Those contracts weren't exactly written after consulting the population...