"Muslim immigrants do not want to assimilate into their host countries." True. It is forbidden in the Holy Quran.
"O ye who believe! Take not the Jews and the Christians for your friends and protectors; they are but friends and protectors to each other. And he amongst you that turns to them (for friendship) is of them. Verily Allah guideth not a people unjust."
"O ye who believe! Take not for friends and protectors those who take your religion for a mockery or sport - whether among those who received the Scripture (i.e., the Bible) before you, or among those who reject Faith; but fear ye Allah, if ye have Faith (indeed)."
"Yea, to those who take for friends unbelievers rather than believers: is it honour they seek among them? Nay,- all honour is with God."
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O ye who believe! Turn not (for friendship) To people on whom Is the Wrath of Allah. Of the Hereafter they are Already in despair, just as The Unbelievers are In despair about those (Buried) in graves."
http://www.answering-christianity.com/friends.htm