There are vast cultural differences, that's to be sure. I firmly believe that immigrant groups should have to assimilate into the countries they become citizens of. As far as I know every single wave of immigrant into the US prior to the 1980's were ready and willing to do this. My ancestors from Europe did. This isn't the case anymore. I don't believe people need to give up every aspect of their culture but it makes no sense to me that they want to flee their dangerous and failing countries for a better life only to attempt to recreate the same country they came from wherever they land. The problem is government could change this but they won't. This same scenario is playing out all over the world.