Much of it has been wasted in overhead and corruption, just as in Afghanistan. Worse, a lot of it went to dictators such as Mobutu, who depended on foreign aid from his Western patrons both to buy support from his clients to shore up his regime and to enrich himself. The picture in much of the rest of sub-Saharan Africa was similar. Humanitarian aid given for temporary relief in times of crises, for example, most recently in Haiti and Pakistan, has certainly been more useful, even though its delivery, too, has been marred in similar problems.
"Why Nations Fail"