Besides crime and different values (women, gays, open society), Germany is one of the most dense populated countries and has 80 Million inhabitants.

How many immigrants do you want to accept? 1 Million? 10 Million? 100 Million? 1000 Million?

Based on the population and fertility rates of the middle east and especially Africa, 1000 Million (1 Billion) would be a number that is not impossible. But, don't you see a problem there?

I agree that "the west" has a moral obligation to ensure people in other parts of the world are not starving to death. But: a 20-year old from Tunesia or Morocco is not starving to death in his home country, nope.