>> Multiple attacks have occurred in or around Paris.

>> NARRATOR: ISIS.

They are the world's most feared terrorist group.

>> Condemning today's bombings in Baghdad... >> NARRATOR: Tonight, the story of where they came from.

>> We created chaos.

We abandoned that chaos.

We created ISIS.

>> NARRATOR: How they waged war for more than a decade.

>> The invasion toppled the government, but Zarqawi ripped the country in half.

>> These people are really prepared to fight the world and demonstrate that in an act of horrific violence.

>> NARRATOR: The failures of two American presidents.

>> The United States government made decisions that seemed to make sense at the time, but without those series of decisions, there would be no ISIS.

>> NARRATOR: Tonight, "The Secret History of ISIS."

>> The guerrilla army that roared east to take over... >> NARRATOR: It was early 2014.

>> ISIS has seized many Iraqi cities.

>> NARRATOR: They seemed to come out of nowhere.

>> In northern Iraq, a number of districts have been taken over by fighters.

>> Militants have swallowed up territory, and they're pushing toward Baghdad.

>> NARRATOR: The terror group ISIS started capturing key territory in Iraq.

>> The jolting gong was when they swept into western Iraq and took control of a third of western Iraq.

The banks that were robbed and stripped, the assets that were stripped in that entire area was huge.

And that was, as I said, the jolting gong that said, "Wait a minute, how could this happen?"

>> Deep concern about ISIS pushing into Baghdad.

>> ISIS has been seizing territory in Iraq.

>> They were able to swiftly take over huge areas of Iraq.

It was shocking how the army didn't even fight, didn't even put a fight.

>> And taking over Mosul, the second largest city... >> I think Washington was stunned when the second largest city in Iraq, a city of two million people, fell in a day.

To a terrorist organization that we had not imagined was in the first order of terrorist organizations.

>> NARRATOR: But these fighters were not new.

They had been at war for more than a decade, ever since the American invasion of Iraq.

They have used beheadings, suicide bombings, and mass killings to implement a violent plan.

A plan designed and carried out by this man: Abu Musab al-Zarqawi, the founder of ISIS.

>> NARRATOR: The secret history of ISIS began at the CIA in the aftermath of 9/11.

There was an urgent question about Abu Musab al-Zarqawi.

>> I was an analyst working on the team that was charged with evaluating whether or not al-Qaeda and Iraq had conspired together to conduct 9/11 attacks.

>> NARRATOR: At the agency's Counterterrorism Center, analyst Nada Bakos was tasked with learning everything she could about Zarqawi.

>> On the team, as an analyst, the big question was whether or not Zarqawi was part of al-Qaeda at the time.

>> NARRATOR: Bakos began by piecing together Zarqawi's life.

>> Zarqawi grew up in Zarqa, Jordan, which was also near a Palestinian refugee camp.

He was a tough kid in a tough neighborhood.

>> NARRATOR: Poor and angry, it didn't take long for Zarqawi to get into trouble.

>> He was a thug.

He was in and out of prison.

He was a petty criminal.

It was rumored that he had worked as a pimp.

>> He was into drugs.

He was into tattoos.

You know, his friends in Zarqa used to call him the "green man" because of all the tattoos that he had on his body.

>> NARRATOR: Behind bars, Zarqawi would undergo a transformation.

>> In this prison, al-Jafr Prison, they allowed him to share cell block with other radical fighters or people who wanted to launch Jihad.

>> In prison, he really came into his own, because he managed to dominate the other prisoners.

He managed to establish himself as a leader.

He took his religion more and more seriously.

>> Zarqawi at the time was the muscle of the movement in jail, and he roughed a lot of people up during his time in jail.

>> NARRATOR: As the "green man" became more religious, he knew his tattoos would be viewed as sinful.

A razor blade was smuggled into the prison.

>> It was brutal.

He had them actually... the skin taken off.

>> It's like he's shedding his old life, and this tattoo was a reminder of who he was, and he had to get rid of that to almost purify himself.

>> NARRATOR: After five years, Zarqawi was released.

>> Zarqawi became a leader among the jihadists in prison and came out of prison in Jordan a jihadist firebrand, had reimagined himself as a mujahid, or holy warrior, dedicated to the establishment of the Islamic empire.

>> NARRATOR: In his quest to become a holy warrior, Zarqawi left Jordan.

The CIA tracked him to Kandahar, Afghanistan.

Zarqawi hoped to meet Osama bin Laden.

>> When he does go to Kandahar to try to meet with bin Laden, he's rejected.

At his point, Zarqawi is so low on the totem pole, and it's just something that was just beneath him.

>> Neither Osama bin Laden nor his deputy Ayman al-Zawahiri were terribly impressed with him.

He seemed and acted like a thug.

He was not very sophisticated.

In fact, they considered him a rather poor recruit to al-Qaeda.

>> NARRATOR: Zarqawi would leave Kandahar determined to continue jihad and to prove bin Laden wrong.

In 2002, he saw his chance.

As President Bush signaled Saddam Hussein had to go, Zarqawi moved to a terrorist camp in northern Iraq.

It set off alarm bells at the CIA.

CIA operations officer Sam Faddis, who ran a kill/capture team, was assigned the case.

>> Headquarters is extremely, extremely interested.

I mean, the number one time-sensitive priority, as of June '02, when I left headquarters, was go collect on this Islamic extremist enclave along the Iran/Iraq border.

>> NARRATOR: It didn't take long for Faddis to find Zarqawi and learn what was going on in the camp.

>> We literally had guys that were working for us that were inside the camp.

They're working on chemical and biological weapons.

They were doing a lot of work with cyanide-based things.

>> NARRATOR: At CIA headquarters, it was a threat they could not ignore if American troops were to invade Iraq.

>> If we took Saddam out, Zarqawi was going to cause a lot of problems.

He was someone who we would have wanted dead if we had the opportunity and the wherewithal to do it.

>> NARRATOR: And Sam Faddis had a plan to do just that.

>> I mean, a handful of aircraft tomorrow, with the specificity that we have in their locations, will end this threat.

And we will finish these guys.

>> This seemed like the perfect moment-- we know where they are, we know what they're up to.

This seemed like the right time to target them and to go after them.

>> NARRATOR: The attack plan was fast-tracked from the CIA to the White House.

But as America prepared to take out Saddam Hussein, the president was told that hitting Zarqawi could cause a problem.

>> I remember there were discussions about attacking various camps that we thought bad guys were hanging out in, and I think the one you're referring to, we made a judgment that, "Let's not start the war before we're ready."

>> NARRATOR: When news of the decision reached CIA headquarters, there was frustration.

>> (laughs): Oh!

I couldn't believe it.

We have a prime opportunity to take out a jihadist that we know poses a threat to our allies, in addition to American forces, once they invade.

>> There was nobody on that team who felt like Washington had made the right decision.

There's another country getting up, ready to go up in flames.

We're giving them time and space.

This will turn out very badly.

We need to get them, get rid of them right now.

>> NARRATOR: But as Vice- President Dick Cheney headed to the CIA, he was preparing to do something else with Zarqawi: use him to connect bin Laden and Saddam Hussein to make the case for war.

>> Vice-President Cheney came to the CIA asking lots of questions.

He wanted to know not only, "Is there a connection between Saddam Hussein and bin Laden?

", but, "We want there to be a connection between the two."

>> NARRATOR: The CIA officers believed there was no evidence of a connection.

>> No, never.

We never found any indication that Zarqawi was in Baghdad working for Saddam or linked up with Saddam.

>> NARRATOR: The vice-president and his chief of staff, Scooter Libby, pushed back.

>> It was pretty intense.

We were lined up on one side of the table, Vice-President Cheney and Scooter Libby were on the other side.

And they walked in with a lot of questions and being very skeptical as to the intelligence that we had been gathering up to that point.

>> NARRATOR: Cheney seemed to want Zarqawi to be the link between Saddam Hussein and Osama bin Laden.

>> The vice-president's frustrated.

His questions are all about Zarqawi, his connection to Saddam, and whether or not they had discussed 9/11, and if Saddam had participated.

>> NARRATOR: Bakos says the vice-president didn't like the answer.

>> We tried to explain over and over again that it would be impossible for him logically to be working with Saddam.

>> There was no connection between al-Qaeda and Saddam Hussein and Iraq that we could find.

Zarqawi's the kind of guy Saddam would kill without a moment's thought.

>> And the response to that was met with skepticism, lots of questions, and a lot more frustration.

>> NARRATOR: But at the White House, the allegations would not go away.

They would appear again as Colin Powell prepared for a speech at the United Nations designed to convince the public to support the war.

>> The speech supposedly had been prepared in the White House in the NSC.

But when we were given what had been prepared, it was totally inadequate, and we couldn't track anything in it.

And when I asked Condi Rice, the National Security Advisor, where did this come from, it turns out the vice-president's office had written it.

>> NARRATOR: Powell would turn to the CIA to vet the speech.

>> We had a copy of the speech that was sent over from the White House that Powell was preparing, and one of our senior analysts was working on it, editing, working on the language to ensure that it reflected our analysis.

>> The speech that will be heard round the world at the Security Council.

>> Powell will try to make the link between Iraq and al-Qaeda.

>> NARRATOR: Just days later, Powell arrived at the United Nations.

>> We have come to another critical moment on the way to a new war with Iraq.

>> Walking into that room is always a daunting experience, but I had been there before.

And we had projectors and all sorts of technology to help us make the case.

>> In this chamber of the United Nations today, the Secretary of State... >> There in the center of attention, Secretary of State Colin Powell and George Tenet, the director of the CIA... >> I think he was very nervous.

Powell doesn't like to read speeches; he likes to have a few note cards and then do his Powell thing.

But this one he read from the text, every word.

>> My purpose today is to provide you with additional information.

>> NARRATOR: At the Counterterrorism Center, Bakos was watching carefully to see what Powell would say about Zarqawi, bin Laden, and Saddam Hussein.

>> We're sitting in our room at CTC watching the television with a copy of the speech in our hand.

>> What I want to bring to your attention today is the potentially much more sinister nexus between Iraq and the al-Qaeda terrorist network.

>> When he got to our portion, it went off our script fairly quickly.

And we were looking around at each other saying, "Where's he at, where's he at?"

We're flipping through pages.

And so, you know, right away, we could tell that this wasn't reflecting the language that we had used.

>> NARRATOR: Powell used Zarqawi to make the connection between bin Laden and Saddam Hussein.

>> Iraq today harbors a deadly terrorist network headed by Abu Musab al-Zarqawi, an associate collaborator of Osama bin Laden and his al-Qaeda lieutenants.

>> It drew conclusions in language we would not use.

So we were very, very, very careful about describing the relationship as we saw it, and it seemed to overinflate and not reflect our analysis.

>> How did that happen, Nada?

>> Within the process of how it went, you know, where it went back to the White House and who worked on it after that, I don't know how it was changed, or by who.

>> NARRATOR: Powell now says the speech was approved by CIA chief George Tenet, but he doesn't remember the details about Zarqawi.

>> Why did he make it into the speech?

>> I don't remember.

Zarqawi was not anything uppermost in my mind.

It was not a significant part of the speech for me.

It was almost a passing reference.

>> NARRATOR: But it was more than a passing reference.

Seven minutes of Powell's speech were devoted to Zarqawi.

His name is mentioned 21 times.

Powell transformed Abu Musab al-Zarqawi in the eyes of the world.

>> From his terrorist network in Iraq, Zarqawi can direct his network in the Middle East and beyond.

>> I can't even imagine what that did for Zarqawi's ego, to be, you know, here he is, his name is spoken at the U.N. Now he's showing bin Laden and al-Qaeda who he really is, right?

He's become this iconic person without ever really doing anything.

>> NARRATOR: In the days that followed the speech, Zarqawi disappeared.

>> Rapid series of 40 explosions lit up Baghdad in the early morning hours.

>> Military officials have been using the term "shock and awe" to describe the assault on Iraq.

>> NARRATOR: Zarqawi watched the American "Shock and Awe" campaign, and as the occupation began, Zarqawi waited for an opportunity.

Before long, the man George W. Bush picked to run Iraq, L. Paul Bremer, gave him one.

>> And those who were on high before, in particular the Baathists... >> NARRATOR: He promised to purge the Iraqi government.

>> ...will be removed from office.

>> NARRATOR: He also issued an order that disbanded the entire Iraqi military.

>> You had something on the order of 250,000 Iraqi men, military age, all trained in using weapons.

Suddenly, they were all out of a job.

>> NARRATOR: The powerful message: Saddam and his Sunni-controlled army were no longer in charge.

>> Army was the central instrument of Saddam's repression of the Kurds and the Shia.

I think the decision not to recall Saddam's Army, from a political point of view, is the single most important correct decision that we made in the 14 months we were there.

>> NARRATOR: But on the ground, the American military commanders could feel the effects.

>> The effect, frankly, was devastating.

I think that's where the seeds of what became the Sunni insurgency were largely planted.

>> We had, you know, long lines of soldiers demanding money, demanding to be rehired.

There was that whole sense of, you know, militaries, defeated militaries should be treated with respect, and that's not what happened.

>> Week after week after week, the big demonstrations got larger and larger.

There was enormous concern because the demonstrations were out of hand.

There were actually killings.

>> They feel like they're going to go by the wayside, that they're going to be not only the minority population, but treated as if they don't matter.

So they were easy targets for Zarqawi to recruit.

>> NARRATOR: Now Abu Musab al-Zarqawi had his opportunity.

(explosion) In the weeks that followed, the insurgency began.

(explosions) >> When these sorts of attacks began, nobody was quite clear, I think, where they were coming from, who was behind them, and how sustainable they were.

>> There has been another spasm of violence in Iraq.

>> A car bomb killed at least five Iraqis... >> NARRATOR: In Washington, they insisted everything was under control.

>> There's an absence of authority, a vacuum of authority for most people.

>> I picked up a newspaper today and I couldn't believe it.

I read eight headlines that talked about chaos, violence, unrest, and it just was Henny Penny, "The sky is falling!"

I've never seen anything like it.

It's just unbelievable how people can take that away from what is happening in that country.

>> Willful denial is one way of putting it.

I mean, I remember, you know, thinking at the beginning, this is really, really strange.

It's one thing to analyze the situation and then spin it; it's another thing to then start to believe your spin.

(explosion) >> NARRATOR: In August, the biggest bombing yet.

>> A massive explosion to the Jordanian Embassy... >> Morning mayhem in Baghdad... >> Terrorists exploded a truck outside the compound... >> This Iraqi runs in, and I said, "What happened?"

And he said, "It was hit by a suicide bomber."

I think that was the first one.

To think that after that, there would be hundreds and hundreds and hundreds of suicide bombers, thousands, even, it's amazing.

>> The bloodshed in Iraq... >> NARRATOR: It was Zarqawi's first major attack.

>> The capital's worst day since Saddam Hussein was toppled.

>> NARRATOR: Then, less than two weeks later, a bomb at the United Nations headquarters.

>> Zarqawi had a strategy.

He's just trying to leave it so that it's only the United States military left, and it's a black and white conflict.

And this will enable him then to rally considerably more support to himself and to his cause.

>> 40 people have died today in a series... >> The immediate effect of that was the U.N. left and all the NGOs were gone within a few weeks, all of them.

And so it essentially left the Americans alone.

That was it.

It's just you.

It turned Baghdad into a kind of eerie militarized ghost town.

>> A U.S. vehicle was on patrol when it came under attack.

>> Violence has returned with a vengeance.

Last night, two more soldiers killed... >> The most deadly was a car bombing that killed at least 11 people.

>> NARRATOR: In Washington, Bakos and other analysts sifted the evidence from the bombings.

Soon, President George W. Bush received a briefing document written by Bakos, but without her name attached.

It outlined Zarqawi's role in the bombings.

>> I wrote a presidential daily brief based on intelligence that we had received that Zarqawi was responsible for some of the major initial attacks in 2003, that he was still there, and that he was looking to foment civil war.

>> NARRATOR: The information made its way to Scooter Libby in the vice-president's office.

(phone dialing) Bakos says she was at her desk at the CIA.

Her private phone rang.

>> I received a phone call at my desk, to my own line, from Scooter Libby's office.

To call an individual analyst is only about pressuring them-- intimidation.

We write these anonymously when they go to the White House; our names are not attached to the brief.

And I immediately told him I couldn't discuss any of this and hung up.

>> NARRATOR: At the vice- president's office, they weren't done with Bakos.

She and her supervisor were summoned for a face-to-face meeting with Libby.

>> We were there because they wanted to figure out how they could poke holes in the analysis.

>> NARRATOR: The questions centered around Bakos's conclusion that there was an organized insurgency led by Zarqawi.

>> There was a lot of consternation in the administration using the term "insurgents" because it would look as if the Iraqis weren't embracing what we were doing.

Insurgency implies that they're fighting against us.

>> Certainly in the fall of 2003, the United States was in denial that an insurgency was brewing.

In fact, that terminology was almost outlawed.

No one could use it.

>> NARRATOR: We wanted to ask the vice-president and his chief of staff about these matters, but neither would agree to be interviewed.

>> Four car bombs went off almost simultaneously.

>> The attacks came during the busy Baghdad commute.

>> At least 35 people have been killed in a huge car bomb attack in Baghdad.

>> NARRATOR: In Iraq, with America's top leaders in denial, Zarqawi was free to raise the stakes.

>> I think the senior leadership of the Bush Administration was slow to realize: A, that there was an insurgency.

And B, that there was an evil genius behind it.

And C, that that evil genius was Zarqawi.

>> NARRATOR: Zarqawi would now send a message to the American people.

>> Zarqawi already had captured people's attention from the succession of suicide bombings.

Now he cultivated a different means to do so, and with someone like Nicholas Berg, I think very tragically, he found exactly the kind of person he wanted: an American, a do-gooder, who was also Jewish.

>> NARRATOR: That's Zarqawi in the middle.

>> If you watch it really closely, it's a Zarqawi show.

He's standing there, he's reading in his guttural voice, he's reading this document.

>> Then he's finished reading, and I'll never forget this.

He finishes reading, and he just hands the script to an aide, who kind of takes it.

It was just like a CEO handing his briefcase to his aide.

And then he pulls out the machete.

>> Allahu Akbar!

>> (screaming) >> It's the only beheading video I've ever watched, the first and last, because it was so horrifying.

You can hear all the noises of the poor man's death and Zarqawi standing over the mutilated body delivering his message to the world.

>> The fact that Zarqawi was killing people personally made him far more appealing to the 20-something Sunni in Saudi Arabia or Iraq or even in Europe, the foreign fighter kind of guy that you want to go join if you're one of those young, disaffected Sunnis.

>> NARRATOR: Finally, Zarqawi had the full attention of the Bush administration.

The American government placed a $25 million bounty on Zarqawi.

>> But it basically puts the same price on his head that Osama bin Laden has on his, and it basically elevates him now to enemy number one for the United States.

>> NARRATOR: Bin Laden had once rejected Zarqawi.

Now he couldn't ignore him.

>> It's shortly after that that the relationship changes.

Zarqawi is the new start-up, and bin Laden wants to invest.

He wants Zarqawi to use the al-Qaeda brand.

So since al-Qaeda hadn't done anything since 9/11, this was a perfect opportunity for bin Laden to get back in the game.

>> NARRATOR: For Zarqawi, it was the seal of approval.

And in a letter to bin Laden obtained by American intelligence, he outlined what he planned to do next.

>> "As the decisive moment approaches, "we feel that our body has begun to spread into the security vacuum."

>> What Zarqawi says in the letter is, "We have one choice, "and that is to start a sectarian war "and basically to set all of Iraq on fire, and to draw in the whole world."

>> "If we succeed in dragging them "into the arena of sectarian war, it will become possible to awaken the inattentive Sunnis."

>> "We're going to foment a civil war, and this will cause "the Shia to overreact.

"They are going to go after the minority Sunni population, "and then the Sunnis are going to have to turn to us, the jihadists, to defend them."

(explosion) >> NARRATOR: Now Zarqawi acted.

(explosion) He initiated unprecedented unrestrained violence against the Shia.

(explosion) (siren blaring) >> 170 people died in that weekend truck bombing... >> Daily life in Iraq: the kidnappings and thousands of killings every month.

>> These killings have created a climate of fear.

>> A wave of sectarian killing across Iraq left at least... >> NARRATOR: Zarqawi was becoming known by a new name: the sheikh of the slaughterers.

>> A suicide car bombing killed 12.

>> Once he pivoted to Shia, Baghdad was just hammered with huge car bombs, but also just daily assassinations... ...of families, of neighbors.

Then you started having those torture cells, the beheading videos...

The invasion toppled the government, but Zarqawi ripped the country in half.

>> God, the horrible, horrible years in Iraq, when there were, you know, hundreds and hundreds of car bombs and suicide bombings, it was incredible what they did.

I mean, it was murderous, it was psychopathic, it was horrific, but it was really extraordinary.

>> NARRATOR: For Osama bin Laden, the violence against fellow Muslims was too much.

Bin Laden's top deputy, Ayman al-Zawahiri, dispatched this letter to Zarqawi.

>> "Many of your Muslim admirers "are wondering about your attacks on the Shia.

"The sharpness of this questioning increases when the attacks are on one of their mosques."

>> So the response from al-Qaeda was, "Stop doing what you're doing.

"Killing Shia and other Muslims aren't going to achieve "the objective that we need.

"This isn't the path that we want you to take, and we're telling you to stop."

>> "My opinion is that this matter won't be acceptable "to the Muslim populace, however much "you have tried to explain it, and the aversion to this will continue."

>> 170 people died in that weekend truck bombing... >> NARRATOR: But Zarqawi disagreed.

His plan for a Sunni resurgence relied on brutal sectarian violence.

>> Attacks are constant and often grisly.

>> NARRATOR: And he would respond to Zawahiri and bin Laden with one devastating attack.

He blew up an important Shia shrine: the Golden Dome in Samarra.

>> Samarra was the straw that broke the camel's back for the sectarian war.

He just took down the biggest revered shrine in Iraq.

And immediately, it was within 12 hours that everything in Iraq changed.

It wasn't it went from good to bad; it went from horrible to unbelievably horrible.

>> NARRATOR: It was all-out civil war.

Tens of thousands would die.

>> And that set off a cycle of violence between Sunni and Shia that al-Qaeda tried to fuel as much as they possibly could, Zarqawi directing it, of course, very capably.

>> Zarqawi achieved what he wanted to achieve.

He had fomented anger and fear and frustration enough that populations felt pitted against each other.

>> NARRATOR: As the civil war raged, Zarqawi decided to do something bold: he would reveal his face on camera.

>> He understood the power of the Internet.

It showed him using an American automatic weapon.

(gunshots) Not necessarily using it correctly, but he did use it in a way that I think established his flair for publicity.

>> It's propaganda.

It's recruitment.

It shows what their intention is.

He's wanting other people to join him.

He's building his army at this point.

>> NARRATOR: In the video, Zarqawi made a surprising proclamation.

He would create an "Islamic state," the first step toward a global caliphate.

>> He was never content just to be the thug from Zarqa, and he wasn't content just to be the guy who beheaded Nick Berg.

He wanted to rule a caliphate.

>> NARRATOR: It was something bin Laden hadn't yet pushed for.

>> Al-Qaeda saw that time as a long way off, and Zarqawi was very, very much more impatient.

He said, "This we can do now."

>> Allahu Akbar!

>> NARRATOR: For Zarqawi, the creation of the caliphate would be the fulfillment of a prophecy.

>> That religious vision promises the return of God's kingdom on earth, the reestablishment of the early Islamic empire, the empowerment of Sunni Muslims around the world.

That the reestablished caliphate will eventually take over the entire globe, and then the entire world will come crashing to an end.

>> The lead aircraft is going to engage it here momentarily with a 500-pound bomb on the target.

>> NARRATOR: The next video the world would see of Zarqawi was very different.

(explosion) In 2006, the U.S. military received a tip and bombed Zarqawi's hideout.

>> The terrorist whose forces set off so many... >> NARRATOR: Zarqawi was dead.

But his call for an Islamic state would live on.

>> Abu Musab al-Zarqawi, the notorious leader of al-Qaeda in Iraq, is dead.

>> Zarqawi's death is a severe blow to al-Qaeda.

It's a victory in the global war on terror.

>> NARRATOR: President Bush seized the initiative.

He ordered a surge of American troops into Iraq to stop the bloodshed.

>> Troops both Iraqi and American will try to slow down the killing among Sunni Arabs.

>> The surge began, but the president stands increasingly alone.

>> The White House is calling its Iraq plan... >> NARRATOR: General David Petraeus was the commander.

>> The priority had to be on securing the Iraqi population, and that this could only be done by living with the people.

So we went back into the neighborhoods in Baghdad and other areas that were threatened by this ever-spiraling Sunni/Shia cycle of violence.

>> $10,000, $20,000, $30,000, $40,000.

>> NARRATOR: Helped by hundreds of millions of dollars, Petraeus made an alliance with the Sunni tribes that had once worked with Zarqawi.

>> The hierarchy in society chopped off too many heads there, taken too many wives from the local population, had upset the power structures.

Guys from the tribes started to turn against al-Qaeda and looked to the U.S. military for support.

>> NARRATOR: One by one, American special forces and former Sunni militants killed Zarqawi's followers.

>> Al-Qaeda in Iraq had been eviscerated.

There were probably 37 individuals that survived that onslaught that we created in '07 and '08 that were really al-Qaeda.

>> The definition of destruction is that you are rendered incapable of performing your mission without reconstitution.

So they're flat on their face, and they're down, and we had our boot on their neck.

>> NARRATOR: What was left of Zarqawi's group would go underground for three years.

("Hail to the Chief" playing) >> NARRATOR: By 2009, the war in Iraq was the responsibility of a new president.

>> President Obama was elected on a promise to get the United States out of Iraq, and he was determined to do that.

>> NARRATOR: And early in his presidency, he announced his plan in front of thousands of Marines.

>> I've come to speak to you about how the war in Iraq will end.

The situation in Iraq has improved.

Al-Qaeda in Iraq has been dealt a serious blow by our troops and Iraq security forces.

>> NARRATOR: For Barack Obama, it was time to move on from Iraq.

>> I intend to remove all U.S. troops from Iraq by the end of 2011.

(applause) >> The last U.S. troops are now leaving Iraq.

>> They're packing up and ready to hand over the remaining... >> After almost nine years of war and thousands of lives lost... >> We disengaged not only militarily at the end of 2011, we disengaged politically.

The war was over.

We were out.

Let the chips fall where they may.

Well, I don't think we thought through exactly how many chips were going to fall and what the consequences of that would be.

>> NARRATOR: Once the Americans were gone, what was left of Zarqawi's group, isolated in northwestern Iraq, began to rebuild.

They had a new leader: Zarqawi's successor, Abu Bakr al-Baghdadi.

>> I mean, he really is a chip off the old block, in terms of Zarqawi.

He has the same sort of sensibilities, the same flair for publicity, the same obsession with widespread violence.

>> They are part of a similar ideology.

They believe in political Islam.

They have a view of the caliphate.

Baghdadi had a Ph.D.

He was a soccer player.

>> NARRATOR: Abu Bakr al-Baghdadi's journey from religious scholar to jihadist leader started back in the early days of the American occupation.

As the U.S. Army conducted mass sweeps of the Sunni population, Baghdadi was put into an American prison.

>> For a number of people who had spent time in these jails, they spoke about them as jihadi training camps.

So through being in jail together, people created new networks.

>> NARRATOR: They were known as "jihadi universities."

Baghdadi learned Zarqawi's methods.

>> He is able to network with other committed jihadists, capable jihadists that were attached to major organizations like al-Qaeda in Iraq, and he begins to network with these men, many of whom he would rise with through the ranks of al-Qaeda in Iraq, later the Islamic State.

>> NARRATOR: After his release, Baghdadi moved up inside Zarqawi's organization.

>> He very wisely played up the idea that his tribe had direct links to the Prophet Mohammed.

And this was very important for establishing his legitimacy as a leader.

>> NARRATOR: In audio recordings, Baghdadi would use his religious authority to justify acts of terror.

>> NARRATOR: And after Zarqawi's death, it was Baghdadi who eventually seized control.

>> Abu Bakr al-Baghdadi was much more assertive and much cleverer and much more ruthless than anyone had thought, and so was able to eliminate rivals, was able to get success.

And success, of course, is a great attracter of support.

>> NARRATOR: As the group's new leader, Baghdadi worked to rebuild, and in keeping with Zarqawi's strategy, he looked for a state in chaos to exploit.

>> Protests continue against the rule of President... >> Across the country, thousands of people took... >> NARRATOR: He saw one across the border in Syria.

>> And a new wave of protests against Bashar al-Assad... >> NARRATOR: Civil unrest was breaking out.

>> It was an ideal set of circumstances for Abu Bakr al-Baghdadi to capitalize on.

>> (chanting) >> NARRATOR: Protests against Syrian president Bashar al-Assad had been met with force.

(gunfire) >> There were peaceful demonstrations.

These were put down violently, and that then sparked this cycle of violence.

>> NARRATOR: As the unrest grew, Baghdadi secretly sent agents into Syria to help fuel civil war.

>> He wanted to establish the caliphate now.

He wanted to take over towns, villages, and then cities.

The border between Iraq and Syria could disappear if his organization controlled both sides of the border.

>> NARRATOR: In Damascus, Baghdadi's men used the bloody methods of Zarqawi's insurgency to announce their presence.

>> I was sitting in my ambassador's residence in the upstairs den, reading, when the two bombs went off.

Immediately, from my time in Iraq, knew those are car bombs.

That's not a normal sound here in Damascus.

>> NARRATOR: Ambassador Ford dispatched a reconnaissance team to the site.

>> We got a sense of how big the holes were and what had happened.

The way the car bombs were delivered, crashing through gates with a follow-on car, was exactly what we had seen the al-Qaeda organization do in Iraq, and so it had the fingerprints of al-Qaeda.

>> The wave of car bombings that convulsed Damascus showed that tactics that been successfully employed in Iraq had now been successfully exported to Syria.

>> NARRATOR: Zarqawi's organization had not only survived, it was growing and starting to capture territory.

>> Two back-to-back explosions hit the capital Damascus early on Friday.

>> Authorities said at least 40 people were killed... >> NARRATOR: Back in Washington, at the State Department, Ambassador Ford was worried.

He wanted to offer military aid to Syrian rebels who were seen as moderates.

>> My team, working in our little offices and cubicles downstairs, began to think we would have to help those more moderate secular elements compete for recruits.

Otherwise, they, over time, would be overwhelmed.

>> NARRATOR: But first, the White House would have to sign off.

Ford had three important allies in the administration: CIA Director David Petraeus, Secretary of State Hillary Clinton, and Defense Secretary Leon Panetta.

They made the case to the president.

>> You did have people inside the administration who said, "We need to get involved here.

"We need to help this opposition force.

"We need to find those who represent values "that we can live with and provide them arms and training."

>> The only way we were going to get credibility with those that were fighting on the streets and dying was to be able to provide the weapons they needed in order to confront Assad, and that's why I supported Petraeus's recommendations and why we recommended that.

>> NARRATOR: Despite the recommendation of his senior advisors, the president was reluctant.

>> ...for us to think that somehow there is some simple solution I think is a mistake.

>> That wasn't something President Obama wanted to do.

He didn't think it would be effective, he didn't want to necessarily get involved in somebody else's civil war.

He came to office not to get involved in the Middle East, but to get us out of the Middle East.

>> Breaking news right now... >> NARRATOR: In Syria, the slaughter of the moderate rebels by the government forces of Assad continued.

>> It is one of the deadliest days in the uprising in Syria.

>> NARRATOR: The barrel bombings, neighborhood after neighborhood.

(explosions) (gunfire) >> They wanted our help.

You know, I think it's fair to say we didn't do much.

We did almost nothing to help them.

Therefore, they're gone.

I mean, they're gone, they're finished.

I mean, as a significant force, they're finished.

>> NARRATOR: Nearly a year later, the president changed his mind.

He authorized light weapons for the moderate rebels.

But it was too late.

Meanwhile, Baghdadi's forces grew even stronger.

>> And the consequences are exactly what the CIA and the Pentagon and the State Department predicted, which was that if the United States isn't shaping the opposition to Assad, radical Sunni groups that look a lot like al-Qaeda will do that.

And they did.

>> NARRATOR: By 2013, Baghdadi's army captured whole sections of Syria.

>> The civil war in Syria gave him an opportunity.

The civil war in Syria gave them a platform.

Now it's not a few dozens hiding in the western desert; now there's thousands and thousands of foreign fighters that's coming from everywhere.

5,000 from Western Europe, 6,000 from Tunisia, almost 5,000 from the former Soviet Union, people coming from everywhere.

>> NARRATOR: Baghdadi finally had what Zarqawi promised: a state.

He called it ISIS and established its headquarters in Raqqa, provoking a final break with al-Qaeda.

>> Al-Baghdadi's success in carving out this Islamic state and putting Raqqa as its centerpiece, as its capital, is a reflection, again, of a strategy that Zarqawi pursues.

>> NARRATOR: And inside its territory, ISIS would rule through violence and fear.

>> I get a steady diet of these videos that they put out, so it's, you know, today, they stoned to death a man, you know, because they suspected him for being gay, or they stoned to death a woman, or they put a man in a car and exploded it, or they skinned somebody alive, or they crucified somebody, or they beheaded somebody, every day.

>> NARRATOR: In Washington, they were struggling to find a successful strategy to deal with Syria.

The new secretary of defense, Chuck Hagel, attended meeting after meeting, hoping one would emerge.

>> In those meetings, there were too many people there.

I'd go into these meetings and every chair was filled in the Situation Room.

You'd have 30 people in there sometimes.

What were they doing in there?

And everybody had a chance to talk.

We rarely got to a conclusion or a decision, and too many people talking, and I think that always leads to an ineffective process.

>> NARRATOR: The president himself resisted authorizing military intervention.

>> The notion that the way to solve every one of these problems is to deploy our military, that hasn't been true in the past and it won't be true now.

>> NARRATOR: The threat of ISIS seemed distant.

>> President Obama doesn't see this emerging group as an existential threat.

He doesn't even see it as equivalent to al-Qaeda in any real way.

"Don't inflate these guys into something that they're not.

Don't make them eight-foot giants."

>> NARRATOR: We asked the White House for an interview; they declined.

Back in Raqqa, Baghdadi was pursuing a new opportunity: the expansion of ISIS into Iraq.

>> At this very time that al-Baghdadi is building his organization in Syria, the Baghdad government, the Shia government of al-Maliki, starts virtually assaulting the Sunni homeland.

>> NARRATOR: In the years since American troops had left, Iraq's prime minister Nuri al-Maliki, a Shia, had initiated a crackdown on the Sunni population.

>> The Sunni Arab tribes in Iraq had become disillusioned with the Shia-dominated government in Baghdad.

So there was widespread disaffection among the tribes.

They began to engage in a series of protests against the regime.

(gunfire) >> And these protests are violently crushed, and in such an environment, that enabled Islamic State of Iraq to rise up out of the ashes and sing "We will protect Sunnis" from Maliki.

>> NARRATOR: It was the moment Baghdadi had been waiting for.

>> Where have the Sunnis to go?

There's only one place they can go.

It is that residual of the insurgency that is now run by al-Baghdadi.

>> NARRATOR: In early 2014, Baghdadi's forces began the campaign to take Iraq.

>> The Iraqi army, which was built at the incredible expense, I don't even know what the final price tag was-- $30 billion?-- largely by the Americans, paid for by the American taxpayer, you know, all their equipment, everything, it all came apart.

>> NARRATOR: In no time at all, they rolled over Fallujah, Ramadi, then the biggest prize yet: Iraq's second largest city-- Mosul.

>> (man chanting) >> NARRATOR: On July 4, 2014, Abu Bakr al-Baghdadi ascended the steps of Mosul's great mosque.

>> Baghdadi never shows his face, but the one occasion that he did was after the capture of Mosul.

>> He wasn't somebody hiding in a cave, somebody you never saw, released secret videos from unknown locations.

He was in a mosque giving a speech and talking about the Islamic state.

>> NARRATOR: From the pulpit, Baghdadi finally fulfilled Zarqawi's dream.

He made it official, declaring himself the caliph: the ruler of the global caliphate.

>> Baghdadi addresses the assembled audience and proclaims himself the caliph and the ruler of Muslims worldwide.

He proclaims the victory of Zarqawi's political project nearly a decade earlier.

They now control a swath of territory containing some five million people, they have a war chest of some $2 billion.

It's a remarkable success for an organization that was soundly defeated in 2009.

>> NARRATOR: Baghdadi had turned Zarqawi's vision into a terrifying reality.

>> On the eve of 9/11, we have 400 pledged members, you know, people who pledged allegiance to Osama bin Laden.

But now they have countries.

They have armies.

They have tanks.

They have missiles.

They have stuff that Osama bin Laden did not dream to have in his wildest dreams.

>> The United States of America is meeting them with strength and resolve.

I ordered our military to take targeted action against ISIL.

>> NARRATOR: In the nearly two years since Baghdadi's sermon, the Islamic State has come under assault from the Americans, the Iraqis, the Russians, the Iranians, and many others.

They have lost territory, but ISIS has already gone global.

>> ...inside the parliament building.

>> Canada's capital is stunned.

>> Copenhagen, Denmark, a city of terror... >> NARRATOR: ISIS conducted or inspired... >> ...horrible scene in northeastern Egypt tonight.

>> NARRATOR: ...more than 90 attacks around the world... >> Multiple attacks have occurred in or around Paris.

>> NARRATOR: ...and have more than 40 affiliated terror groups in 16 countries.

>> ...massacre in San Bernardino today.

>> The attack left at least 14 people dead... >> NARRATOR: They have promised that the worst is yet to come.

>> ...from what investigators say was an ISIS suicide bomb attack in Turkey.

>> Now Belgian officials say 34 people were killed and 187 were wounded in two explosions.

>> And after today's horror, the question is, how many more terrorists are ready to strike?

>> Go to pbs.org/frontline for more on how ISIS has spread beyond Syria and Iraq.

Read extended interviews with Colin Powell... >> We made a judgment.

>> ...and Nada Bakos.

>> I can't even imagine what that did for Zarkawi's ego.

>> Explore the Frontline archive of reporting on the ISIS threat.

And connect to the Frontline community on Facebook and Twitter.

And if stories like this matter to you, then sign up for our newsletter at pbs.org/frontline.

>> Sandy swirls along the East Coast.

>> Thousands of us are still not home yet.

>> You would talk to one person and then another person, you would get a totally different story.

And nothing's been accomplished.

>> I saw blanket denials across the board.

>> $400 million in profit.

How do you explain that?

>> Well, we were providing oversight.

It was not enough.

>> Frontline and NPR investigate "Business of Disaster."

>> For more on this and other Frontline programs, visit our website at pbs.org/frontline.

Frontline's "The Secret History of ISIS" is available on DVD.

To order, visit shopPBS.org or call 1-800-PLAY-PBS.

Frontline is also available for download on iTunes.