The IMF primarily.

Yes the US takes part in that, but the organization is the IMF.

The IMF partially realizes their role in this, but its more of an outcome than a conspiracy. They've commented on that book in an interesting non-denial, basically saying that the GDP of the countries they've helped/subjected-in-a-giant-conspiracy is so low and such a small fraction of the IMF budget that it doesn't make sense that they would put much effort in it.

In any case, its just the terms of their contracts. Country can't pay, country must raise taxes or expropriate goods, or find natural resources.