I personally believe that multiculturalism actually hinders integration. As integration happens a society can evolve TOGETHER with facets of individual cultures being absorbed into one, whereas multiple cultures will always have dividing lines.
A definition of tolerance - the willingness to accept or allow behaviour that one dislikes or disagrees with.
Personally I would rather see something done than just accept the killing of school children.
The obvious terrorist suspects often take a while to claim responsibility, but we should not ignore the likely inspiration for this atrocity, to do so is just burying our heads in the sand.