The words spoken by David Cameron last Saturday at the security conference in Monaco are arousing fierce controversy in Britain. Echoing what he said few months ago, Angela Merkel, and ideally by referring to the speech given in 2005 by Tony Blair in the aftermath of the attacks on the London Underground, Cameron said that "multiculturalism has failed", citing the end of what we call an attitude of "feel-good" against all the manifestations of Islamic extremism, as it would have planted roots in the Western democracies.