Bender and Fry hatch a plan to join the military to gain 5% discount cards given to all military personnel, buy gum from a store and then quit. Playing the military for chumps.
Their plan goes awry when war is declared and their resiginations will no longer be accepted. In an attempt to help stop her friends being killed Leela tries to join as well but the military are no longer accepting female recruits, not while Zapp Brannigan is in charge, so she is forced to disguise herself as a man to be accepted into their ranks.
The best scene is when after the first battle against their foe goes poorly. President Nixons head places a bomb inside Bender designed to blow when he (Bender) utters a single word. Ass. When Bender discovers this he turns this predicament in his favour by making demands and threatening to blow himself up if they are not met.