First of all, as soon as we hire foreigners, it saps our own economy, which could be a selling point at home. That's not to say that hiring them would not be good, sure, it'd be great for them, short term. But also, this sort of gigantic effort being plopped down into a poor country runs the risk of dominating its economy and turning it into a state that can't afford to lose the program once it's done. And what do you pay the workers with, and how does it limit inflation? You can't expect the foreign government to pay its own workers for a project it can't afford, and if it prints its own money and then taxes its population, like us, to control inflation, it likely wouldn't be able to make up the taxes to control the amount of inflation that would occur; it would devalue their currency to the point of their entire economy being destabilized and everyone getting screwed.