Immigration in US is different from immigration in Europe. America is a country of immigrants excluding the native americans. It is a new country only about 3 to 4 centuries old. So it really does not have a strong culture or a cultural model it could claim to be its own. But most European, mainly western european countries are very old with strong history and culture. And when a group of immigrants move in and try to change the host country's culture, it creates a lot of rifts. And that is precisely what is going on in Europe these days. And the question about immigrants complaining about US policies, why not? Just because you do not like the chef who makes an excellent dish does not mean you should not eat his food. Well as long as you are not hurting the chef. Besides US is ruthless and arrogant and ignorant when it comes to foreign policies.