The choice to destabilize their countries for economic or politcal gain. For example people have to leave Central America largely due to the CIA's interventions in democratic elections. They want a leader who will do what America wants even if it's a Democratic one. In South America the cocaine trade of which the CIA is involved and America the #1 customer have the same results. People are so quick to say this happens because of Socialism but it's not always the case. In Africa war lords depend on the diamond money from western consumers. It's a useless rock that is not in short supply at all and we place value on it. We can even create this rock in a lab but women are told he does not love you if a small child did pick a real one while a AK-47 was pointed at him. There is war because we aid it. I don't think these people hate white people enough to overrun them as some kind of revenge.