Before Abu Musab al-Zarqawi was blotted out by a US airstrike on June 7, 2006, he made an impression, especially on Stanley McChrystal, who, as a lieutenant general in charge of US Joint Special Operations Command, led the effort to take out the leader of Al Qaeda in Iraq.
Al-Zarqawi's zealotry made him a lodestar for an extremist movement that still roils Iraq and the region, McChrystal said on a recent episode of Business Insider's "This Is Success" podcast.
"For about two and a half years, we fought a bitter fight against this guy. And Abu Musab al-Zarqawi had come from a tough town in Jordan, very little education, got involved in crime and things like that in his youth," said McChrystal, who profiled al-Zarqawi in his most recent book, "Leaders."
"But then, what happened was he realized that if he showed self-discipline to exhibit the conviction of his Islamic beliefs — if he did that overtly, if he became a zealot — other people were attracted to him," McChrystal added. "He was living up to what he said and was demanding that they do."
Arriving in Iraq in 2003 to lead a US Joint Special Operations Task Force, McChrystal recognized the strengths of Al Qaeda in Iraq and the mismatch the group presented for the US military's traditional conception of its enemies.
"By habit, we started mapping the organization in a traditional military structure, with tiers and rows. At the top was Zarqawi, below him a cascade of lieutenants and foot soldiers," McChrystal wrote in 2011, a year after retiring. "But the closer we looked, the more the model didn't hold."
AQI's network was characterized by the free flow of information and resources.
Tactics changed quickly across broad swaths of Iraq. It became clear that Al Qaeda in Iraq was less a hierarchical fighting network than "a constellation of fighters" organized by relationships and reputations.
At the center was al-Zarqawi.
"When he became the leader of Al Qaeda in Iraq, he led the same way. He wore all black [and] looked like a terrorist leader," McChrystal told Business Insider correspondent Richard Feloni.
In 2004, al-Zarqawi beheaded American contractor Nicholas Berg, McChrystal said.
That was "a gruesome thing to do," he added, but it served as a message that "'our cause is so important, I'm willing to do something that we all know is horrific.'"
"He was able to bring forth people to follow his very extreme part of Islam when most of them really didn't," McChrystal said. "The Iraqi Sunni population were not naturally adherents to Al Qaeda, but yet he was able to produce such a sense of leadership and zealous beliefs that they followed. He became the godfather of ISIS."
In summer 2005, McChrystal was recalled to the White House to brief the National Security Council on al-Zarqawi.
"Are you going to get him?" President George W. Bush asked McChrystal.
President George W. Bush.
(White House photo by Eric Draper)
"We will, Mr. President," McChrystal replied. "There is no doubt in my mind."
As US forces whittled away the middle ranks of al-Zarqawi's organization, which he had built into semiautonomous cells, the Al Qaeda in Iraq leader was seeking to ignite a sectarian war, stoking violence between Sunnis and Shiites.
By spring 2006, al-Zarqawi was a bigger priority for JSOC than Al Qaeda cofounders Osama bin Laden or Ayman al-Zawahiri, the latter of whom is still alive.
By May that year, JSOC had mapped out al-Zarqawi's organization around Baghdad, including his spiritual adviser, with whom he met frequently.
On June 7, 2006, a drone tracked the adviser to a house in Hibhib, a village roughly 12 miles from McChrystal's own headquarters, where US personnel watched intently as a man dressed black walked out and strolled through the driveway.
Just after 6 p.m., an F-16 dropped a 500-pound laser-guided bomb on the house, following it with another less than two minutes later.
A U.S. Air Force F-16 Fighting Falcon.
(U.S. Air Force photo by Master Sgt. Andy Dunaway)
Less than 20 minutes after that, US Army Delta Force operators arrived at the demolished house to find Iraqi police loading a still-alive al-Zarqawi into an ambulance. They watched him die.
"We didn't just depose him. We killed him," McChrystal told Feloni. "I stood over his body right after we killed him."
McChrystal expressed no admiration for al-Zarqawi's methods — "in many ways, he was a psychopath," he said — but he acknowledged al-Zarqawi's strengths as a leader.
"Your first desire is to demonize him, but you know the reality is I had to respect him. He led very effectively," McChrystal said.
"Initially you just say we're just going to get this guy, and then after a while you watch him lead, and you realize not only is he a worthy opponent, he's making me better, [and] you're also going after someone who truly believes," he added.
McChrystal held his position in Iraq until 2008 and was credited with making JSOC more agile and more lethal, evincing "an encyclopedic, even obsessive, knowledge about the lives of terrorists" and pushing his command to kill as many of them as possible.
He took over command of NATO forces in Afghanistan in 2009, but his tenure was short-lived.
He resigned in the summer of 2010, after the publication of a Rolling Stone article in which his aides were quoted disparaging US officials, including Vice President Joe Biden.
Vice President Joe Biden.
The killing of al-Zarqawi looms large among McChrystal's accomplishments, though he said that operation was reflective of how he learned to decentralize responsibility rather than indicative of his martial prowess.
"The myth is the counterterrorist who killed Abu Musab al-Zarqawi — went out, wrestled him to the ground, bare to the waist, and that's total BS," McChrystal told Feloni, when asked how he would describe his own biography.
"At times, do I like the myth, because people go, 'Wow, look at him'?" he said. "Yeah, it's kind of cool, and you never want to go, 'no, that's not true.' But it's not true."
"The reality is that I built the team" that took out al-Zarqawi, he added. "Ultimately I'm more proud of enabling the team than I would be of wrestling [al-Zarqawi] to his death."
This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.