On GPS Sunday, Fareed looks at the battle against ISIS. First, as a debate wages about the group's ideology, a panel weighs in on how to describe and deal with the phenomenon President Obama calls "violent extremism." And, a new battle against the terror group heats up, online. Then, John Chambers, chairman and CEO of Cisco, explains how the spread of disruptive technologies will transform lives. Finally, is American power a symptom of luck? And how long will the U.S. remain on top?