Zakaria: How ISIS has thrived

Story highlights

  • Fareed Zakaria: ISIS has thrived because of a local Sunni cause in Syria and Iraq
  • Leaders of ISIS have recognized they are a messaging machine, he says

This is an adapted version of the conclusion to "Blindsided: How ISIS Shook the World," a "GPS" special airing Sunday at 7 p.m. ET on CNN.

(CNN)It's easy to be anxious about the threat posed by the Islamic State of Iraq and Syria. After all, this is a brutal organization that not only kills but seems to revel in doing so in ways designed to shock the world -- from the beheadings of journalists to burning a Jordanian pilot alive. Such moves are part of this murky group's propaganda and its deliberate efforts to manipulate information.

So what can and should we make of the organization?
    I explore the issue in depth in a special airing Sunday night. And although it's important to start with the caveat that ISIS is indeed trying to scare and confuse us, I took away some tentative lessons from speaking with the people who have traveled inside the minds of ISIS.