nto such serious foreign debt problems and what are the implications of this debt for both the economics of less developed and more developed nations?...

how did THIRD WORLD nations get into such serious foreign debt problems and what are the implications of this debt for both the economics of less developed and more developed nations? 

why is there so much unemployment  in the THIRD WORLD, especially in the cities, and why do people continue to migrate to the cities from rural areas even through their chances of finding a job are very slim?