Well Law, it was merely a first thought and I haven't worked out the actual economics of it, but if dictators start getting dictatorial, the money-company has the cards. It can always pull up stakes and leave, or deal with their adversary in any number of ways which would probably not be legal here in the U.S.
Of course, given the military power held by most African dictators, they might just nationalize the company. But all the American expertise would be gone, so it would just drop into its own sinkhole.