Filmed over 18 months, the series features incredible access from inside the walls of the Pentagon to the front lines of the U.S. military's mission to fight global extremism around the globe. The global event series, from National Geographic Studios and showrunner Scott Boggins, of the critically acclaimed hit series "The Circus: Inside the Greatest Political Show on Earth," will premiere on Monday, Jan. 15, at 9/8c.

For every agent in the United States Secret Service, the most high-profile security assignment is to protect the president of the United States. In National Geographic's documentary series Chain of Command: The Secret Service viewers will be immersed in the high-stakes world of a law enforcement agency that very few people know much about. The second season of the Chain of Command franchise will premiere in early 2019 after National Geographic camera teams embed with the elite agency over the course of a year.