Admiral Theodore McKee is retired, when following the events of 9/11 he receives a call from the White House informing him that his commander in chief requires him to serve his country once again.

Such subplots include the invasion of Afghanistan, use of precision-guided air strikes with weapons such as GPS-guided JDAMs, the Customs agent on the Canadian border stopping the vehicle carrying explosives for the attempted Millennium bombing, the pursuit of Osama bin Laden and the destruction of Al'Qaeda training camps in the Middle East, as well as in the beginning of the film.

Admiral McKee's daughter, Melissa, is due to leave New Jersey for San Francisco on September 11, 2001, on United Airlines Flight 93.

The jet pilot is ordered to stand down, take a deep breath, and escort the airliner to O'Hare International Airport in Chicago, where Melissa first vigorously demands to know if they had almost been shot down.

As one review said "And don't be fooled by names like Tom Skerritt and Scott Glenn; Homeland Security is a bland and fairly tasteless bullet-point history lesson on how the 9/11 attacks happened, how a bunch of generic TV characters deal with it, and how many soaring musical strains can be employed while the rah-rah chest-thumping speechifying goes on in front of a flapping American flag."