The question isn't "is it a problem?"
The right question is: "whose problem is it?"
This is why we have BORDERS. So our President here in the US (and it better be Obama) isn't responsible for some starving kids in run down nations that have been governed like crap forever.
This whole world citizen thing is nonsense. The US didn't become what it was overnight. Originally, it was colonists from the Mayflower and Jamestown struggling to survive. Then more people came, we got the 13 colonies, overthrew the British, had a civil war, manifested destiny, and more or less stayed out of world events until the world wars at which point we sort of were forced into our current position.
I say it's time to scale back again and say fuck you to the rest of the developing world. We owe them nothing. Not our problem.