At the Springfield Mall, two United States Army recruiters fail to tempt Jimbo, Dolph and Kearney. Realizing that even the dumbest teenagers in the dumbest city in the dumbest US state do not want to join the Army, they decide to start targeting children. During a surprise assembly at Springfield Elementary, the recruiters show a short movie depicting the Army as a high-tech adventure. According to the film, soldiers fly around in helicopters destroying evildoers by day and rocking out in front of thousands of screaming fans by night. The students are easily swayed and quickly line up to enlist.
An excited Bart comes home from school and shows Homer and Marge his delayed entry program form. Though Homer is impressed, Marge is appalled at the idea of Bart joining the Army when he turns 18, prompting her to send Homer down to the recruitment center to get Bart out of his contract. Homer reluctantly forces the two recruiters to tear up Bart's paperwork, though he apologizes for it, saying that it was Marge who told him to do so. Upon learning this, the recruiters prey upon Homer's gullibility and convince him to enlist instead. At the post Homer infuriates his new hard-nosed colonel (Kiefer Sutherland). Homer loves the sound of the colonel's noticeably "awesome" gravelly voice. While the majority of recruits are assigned to the infantry, Homer, and a group of stupid recruits, are assigned to a rehabilitation platoon. During field training exercises, Homer and the other stupid recruits are given the role of the opposing force, (China). Upon learning that it is a live fire exercise, with the weapons to be tested on them, the unit tries to hide. Homer, mistaking gunfire for Chinese New Year, accidentally exposes his unit's location by launching a flare. The flare blinds the colonel and his men, who were all wearing night vision goggles. Homer and his unit soon escape into Springfield while the Army gives chase.
As the colonel and his troops patrol Springfield searching for him, Homer sneaks back home. Marge and Homer are surprised by a camera equipped toy helicopter and (in a scene reminiscent of many classic cartoon chases) Homer attempts to avoid it, running through the entire house, eventually leading the helicopter into a downstairs closet full of TNT and dynamite. He locks the door behind the UAV and the closet explodes. To avoid the army, Homer reluctantly hides out at the Retirement Castle. Marge rallies the Springfield community in coordinated resistance to the occupiers through a word of mouth campaign. The citizens spike the town reservoir with alcohol, intoxicating the occupying forces. The colonel's resulting hangover is so great he reluctantly surrenders to the townsfolk, stipulating only that Homer finish his enlistment. Homer does so by becoming a recruiter.
During the closing credits, a martial scoring of The Simpsons theme plays and the colonel voices "frontline infantry" assignments to nearly every cast and crew member (one exception being Kiefer Sutherland, who is assigned to the United States Coast Guard), as the credits roll over the usual black background.