Empires rise and fall, and one of the reasons is they get soft and try to be all noble and ethical and stop defending their own interests aggressively. So they get taken down by others who aren't so nice. Happened to Rome, happened to Britain (though that was mostly self-inflicted rolling over and giving in) and eventually it will happen to the USA. (Nothing lasts forever, don't fool yourself.)
Would be nice to think we're over that stuff in the 21st century, but that is clearly not the case.
Scary to note that mass migration played a part in the fall of the Roman Empire, and there are similarities to today's surge in migration.
http://www.history.com/news/history-lists/8-reasons-why-rome-fell
"The Barbarian attacks on Rome partially stemmed from a mass migration caused by the Huns’ invasion of Europe in the late fourth century. When these Eurasian warriors rampaged through northern Europe, they drove many Germanic tribes to the borders of the Roman Empire. The Romans grudgingly allowed members of the Visigoth tribe to cross south of the Danube and into the safety of Roman territory, but they treated them with extreme cruelty."
And in this enlightened age when it's plain that all people are at their core pretty much the same, it would be nice to abandon the concept of nationality altogether. But those who seem to be attempting to make that happen aren't facing up to the fact that scrapping borders inevitably leads to wealth redistribution. Poorer nations benefit, richer nations lose out. Again, all very noble, but not in the interests of the better-off countries. And I for one don't see why this wealth redistribution should be forced on us.
Anyway ... here's a weak attempt to get back on topic: