A new FRONTLINE special from director Michael Kirk explores how the Bush administration’s reaction to the September 11th attacks led to America’s deadly and costly wars in Afghanistan and Iraq and changed domestic U.S. politics for generations to come. Filmmaker Michael Kirk joined Jim Braude on Greater Boston to discuss.

The film draws a line from 9/11 to the insurrection on Jan. 6, 2021.

“From the very beginning, when patriotism was in the air and the world was with us and we’d been attacked — something else got in the political blood as well, which was fear,” Kirk said. The film investigates the “division, polarization, lack of trust and faith in government” that followed 9/11.

“When you do the arithmetic on all of it, as we did in the film, you get to the end and you realize that the nation has been divided in a way that it’s never really been divided before,” he added. “And when that is weaponized by the former President Donald Trump, what it resulted in was the attack on Congress on January 6.”

WATCH: New Michael Kirk film explores how 9/11 changed the course of U.S. history