I think you're going to find that as huge parts of Africa and the Middle East cease to be capable of supporting the large number of people who live there, you will see migration like never before. You think people fleeing from absolute misery are going to care that their welcome will be less than warm?

For now it's a relative trickle, but given time and a lack of care and you'll see floods. As you say, look at the backlash... imagine what a 10x or 100x backlash will look like. Now remember that we all have nuclear weapons on a hair trigger.