The founding father of ISIS emerged from a Jordanian prison dedicated to the establishment of an Islamic caliphate — and as the 2016 FRONTLINE documentary “The Secret History of ISIS” reveals, there was a moment more than a decade ago when CIA insiders say they could have stopped him.

In the few short years since the Islamic State of Iraq and Syria formed, it has done the seemingly impossible, seizing vast areas of the Middle East to form a mini-state it calls a reincarnation of the ancient Caliphate. It is at war with all its neighbors and virtually the entire world.

To understand how this terrible group came about and how it has grown so powerful, you need to understand the story behind its rise. And that is a story that goes back decades, to long before ISIS even existed.

Watch the FRONTLINE PBS Full Documentary for the full story: