I believe she's traveled...
and I believe aris2chat has traveled...
though their perspectives differ - their posts are interesting and informative...
I believe your husband has traveled...however, you are making claims to knowledge by riding on his coat tails, so your knowledge is second hand.
If he can tell Shaarona a thing or two, by all means invite him to join USMB
That is still true with today's immigrant groups, and even in Europe. Where there are "hold outs" as you say - there are also mitigating factors that we don't have in the US nor in the UK.
Citizenship is a big factor in integration into the larger culture - countries with a history of guestworker programs have large populations of foriegn non-citizens (usually without their families) living for years but with no possibility of citizenship. I think that discourages assimilation and it is also often reinforced by segregation based on economic levels and class.
Another factor (I don't recall where I read this) pertains to those countries, like France, who offer citizenship to anyone from it's former colonies. Unlike Britain, France's former colonies were often poor and left in bad shape when they attained independence (England tended to invest heavily in civil service and infrastructure in their colonies and attracted immigrants that were at a higher educational level). Also, many of the immigrants to France came from very poor and very uneducated regions (for example rural villages in Algiers) and when they immigrated, they tended to import their (uneducated) religious leaders. That kind of population can make integration harder especially when coupled with a larger economic and cultural segregation and lack of good paying jobs to encourage upward mobility.
That's something we, in the US, have not experienced.