"What makes these 17-year-old kids pick up an AK-47 instead of trying to start a business?" It's a question U.S. State Department spokeswoman Marie Harf asked on MSNBC's "Hardball." She was on air to give a preview of this week's White House summit on "countering violent extremism."

And it's also a puzzle that has confounded the U.S. government since the Sept. 11 attacks. In order to make a long-term dent in the conflict that used to be known as the war on terror, one has to ask why people join these murderous organizations in the first place.

Presidents George W. Bush and Barack Obama have both spoken of such root causes. Harf suggested in her remarks that the West should address economic misery and poor governance to stop young people from joining the violent jihad. But is she correct?