Terror experts: The difficulties in fighting ideology

(CNN) – Terrorists are often initially initiated into extremist Islam not by preachers who preach violence, but by preachers who preach hatred without violence, British Prime Minister David Cameron said at the United Nations Wednesday.

How can Western powers combat such a problem?

Former Homeland Security adviser and CNN national security analyst Fran Townsend, and Foundation for Defense of Democracies senior fellow Daveed Gartenstein-Ross discuss.