If you build a large Islamic population..the extremists will infiltrate. Even the moderate Islamics will warn you of that. Listen to the word in the mosques or keep dreaming that these barbarians can be "loved" enough to give up their zealous ideas and laws.
Thats almost a no brainer, another example of that same logic is if you build a bigger city there will be more crime. That is not really the right way to look at the problem.