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LOS ANGELES – The new eight-part documentary series "Chain of Command" is being promoted by the National Geographic Channel as offering an unprecedented look at the war against violent extremism and the men and women devoting their lives to it.

To get that perspective, film crews were embedded during the 18 months of production with military forces in some of the more dangerous spots on the planet.

The series, narrated by Chris Evans ("Captain America") debuts Monday with a look at the battle for Mosul, Iraq, where Capt. Quincy Bahler of the 101st Airborne Division monitors ISIS fighters via drone feeds alongside Iraqi generals, debating when it is safe to strike in an effort to liberate the city.

The debut episode will be followed by another episode in Iraq, after the American and Iraqi coalition gain control of eastern Mosul, and the fight shifts to the city's west side. Meanwhile, on the Caribbean island of Trinidad, the Muslim community struggles to deal with the alarming reality of their young people leaving the country to fight for ISIS.

"It's been an amazing experience to be able to meet and then tell the stories of these heroes," said executive producer Scott Boggins. "They're inspiring individuals from the highest levels of the U.S. military to the boots on the ground."

The series records the fight against radical threats in every corner of the world as it unfolds over one full year.

This includes following Gen. Joe Dunford and the Joint Chiefs of Staff creating policy and strategy that is then executed on the battlefield, revealing firsthand how the decisions made at the Pentagon have a direct impact on our service members fighting on the front lines.

'Focus on the story'

Even with access, getting the story was a challenge because the teams were in remote parts of the world. The filmmakers wanted this to be an immersive series, Boggins said. The key was learning how to adapt and follow the lead of the military.

"When you're in an area that's in active conflict, the military [is]working on their time, and they're not going to slow down for you or your crew," said Jessica Phillips, a field producer who was embedded with troops outside of Mosul. "You have to get on their time. You have to be present 24/7.

"When things get a little hairy, you have to focus on the story and make sure that that's your focus."

One of the concerns when a film crew or journalist gets embedded with the military is they form a bond that can change the way the story gets told.

Capt. Greg Hicks, special assistant for public affairs to the chairman of the Joint Chiefs of Staff, said the military never asked the filmmakers to add or omit anything. What was asked, he said, was to document the lives of the men and women in uniform and to tell the story of what they are doing.

Jeff Hasler, head of development and production at National Geographic Studios, stresses that edits were made by the film team.

"For us, we have a 188-year tradition at National Geographic of journalist integrity, accuracy, and everyone who works at National Geographic carries that like a banner," he said.