you find large ex-pat communities most countries. we have had wave after wave of foreign people coming here to settle for years its noting new. west indies are now what 5th 6th generation British?
as for the 'it will happen here' thing. wasnt there a Muslim uprising in Yugoslavia? not nice all the ethnic cleansing but shows it cant happen. we are a country of 60m people the Muslim community accounts for around 2% of the population. and the hardcore nutters are going over seas to fight and hopefully die.