"Janet Napolitano Reviews Peter Bergen's 'United States of Jihad'" The New York Times

Janet Napolitano remarks that after reading Peter Bergen's book, "one can only conclude that where American jihad is concerned, the sole constant is change. Al Qaeda has already spawned numerous spinoffs. The most recent and violent iteration is ISIS. Our security agencies and law enforcement must continue to adjust and improve, and the public itself must play an ever more important role, even as the risk of another attack such as the one in San Bernardino cannot be eliminated."