Are we weak, dry-rot rotting from the inside out?

In regards to Islam specifically (with it's warts intact), is multiculturalism still constructive? Has this value failed us (made us vulnerable/been exploited)? If no to the former and/or yes to the later, can it be made a valuable ideology again if it is made subject to certain conditions (so that it doesn't trump all other values/freedoms--such as free speech, religious tolerance (for all faiths) and the freedom to practice that faith, gay rights, security & safety, a celebration of a true mosaic society (free from censorship in the name of not offending anyone), and the rightful celebration of our Canadian heritage)?