It would be a fine idea if outside influences were to leave off meddling in Africa, and one or two other places, but vested interests being what they are I would deem it impossible to achieve.

If memory serves, the last nation to cut itself off from the world with any degree of success was Japan. That was before the world was shrunk by modern communications, pan-continental companies etc. The attempt eventually failed, and that was a relatively small country with limited resources to tempt outsiders.

The idea that left alone the indigenous people might simply wipe each other out is a pretty horrible possibilty, though a remote one IMO. It could well appeal to some of the powers and business interests which eye Africa's resources with such greed. What would prevent their addopting such a plan is that it would take more time than they care to invest, so they try and hurry the process along a bit, resulting in the mess we see today.

I will grant that much outside interference has a benign intent, some has a positive effect, but much is harmful, and a great deal is in truth self-interest wearing the clothes of altruism.