15-year-old Erik Sanderson witnesses two SMG-toting men attacking neighbor Ernie Braden (himself a corrupt police sergeant and Erik's former baseball coach), grabs his .22 lever-action and runs to help. Though he's too late to prevent Braden from being shot dead, the boy drives off the killers, mortally wounding one of them with a headshot.
Chavez's unit (barely about platoon strength), taking down the great majority of a company and half of drug-lord mercenaries, in what is aptly named the Battle of Ninja Hill.
John Clark making the Director of Operations at CIA damn near piss himself in fear of the guy.
The Director of Operations himself easily outmaneuvering Admiral Cutter in his own office to get an authorized Presidential order entitling him to carry out the operation and thus covering his ass.
Clark avenges some fallen soldiers in the most hardcore way possible.
Ryan brings in a Gunship Rescue for the last team with an Air Force MH-53 Pave Low, with three Gatling Good miniguns, one of which Jack mans. Cue asskicking as the assembled mercenaries are slaughtered.
Jack gets one that overlaps with Crowning Moment of Heartwarming when he swears to the dying Sergeant Zimmer he will make sure his kids get into college. Throughout the whole book, US government officials have been regarding people like Zimmer as faceless, expendable cats-paws to do their dirty work, make them look good, and in the worst cases, die and take their secrets to the grave so they don't get in trouble, and none of the people in and out of uniform doing the work of stopping narcoterrorism get any gratitude or acknowledgement from a government that even sinks to the point of cutting their own troops off and leaving them to die to tie up loose ends and cover their own asses, a fate Zimmer almost shares. Jack, of his own initiative, decides to make sure his death wasn't in vain and swears he will ensure the wealth and livelihood of a family whose father died in the line of duty, proving to the dying man he didn't die for nothing and that at least one of the people responsible for his fate is willing to repay his loyalty.
The SUV ambush staged by Cortez to make the Cartel and his own boss vulnerable to U.S. anger. A nail-biting action scene and the best-remembered bit of the movie.
At the end of the movie, Ryan gives the President a brief but powerful "Reason You Suck" Speech in the Oval Office. The President responds first by trying to browbeat Ryan ("Don't bark at me like some junkyard dog!"), then threatening to ruin the late Adm. Greer's reputation as part of a promised cover-up. Finally, he tries to get Ryan to agree to keep quiet, in return for a future favor from the White House. The President refers to this as the "Potomac Two-Step", and Ryan just glares at him and says, "Sorry, Mr. President. I don't dance."
The credits roll just as Ryan is being sworn in to testify before Congress. He's determined to do the right thing even if it means defying powerful figures and all the fallout that implies. It also suggests The President will soon face the worst Executive Branch scandal since Watergate.