When three small-town National Guardsmen, Larry McCoy (Larry the Cable Guy), Bill Little (Bill Engvall), and Everett Shackleford (DJ Qualls), accidentally find themselves in Mexico instead of Iraq, their bizarre misadventures lead them to take on a gang of corrupt Bandidos while "liberating" a local village.
Larry, struggling after losing his job, faces the news from his girlfriend Karen that she is pregnant with another man's child. Bill grapples with marital issues involving his wife Connie, while Everett finds himself living in a storage locker after a mishap with his former job as a police officer. To help his friend heal from his heartbreak, Bill shows Larry a rather unconventional method of moving on—by shooting the gifts he bought for Karen.
Meanwhile, an Army Colonel requests additional troops for Fallujah, leading Master Sergeant Kilgore to assess the local reserve base where Larry, Bill, and Everett are stationed. After a grueling training course, they are unceremoniously sent off to Fallujah. However, a twist of fate finds them dozing off in a Humvee aboard a cargo plane, which soon leads to chaos when a bout of turbulence causes them to tumble out, with Kilgore still attached to medical supplies.
Upon waking the next morning, the trio believes they have landed in Iraq. A series of misunderstandings leads them to mistakenly bury a fellow soldier, Kilgore, thinking he has died. Their morose eulogy is accompanied by an awkward prayer from Everett about Powerball. Gearing up for what they think is combat, Larry humorously quips, > "All right ladies...Let's Git R Done." Yet, in a comical turn, they have actually landed in Central Mexico.
As they navigate their surroundings with a map of Iraq, their misbelief intensifies when Everett takes aim at two Mexicans and accidentally kills their mule instead. Unexpectedly, the Mexicans ask for their help in saving their village from criminal elements. Meanwhile, Kilgore re-emerges alive, realizing he’s in Mexico after an unpleasant encounter with a canteen filled with urine.
Determined to aid the villagers, Larry, Bill, and Everett concoct a half-baked plan to confront the "Iraqi Insurgents," only to discover that their true enemy is a band of local thugs led by the villainous Carlos Santana (played by Danny Trejo). As their "Operation: Sombrero" unfolds, Bill's attempt to call for help leads to him being captured. With quick thinking, Larry reassures him that they can take down Santana, which leads to an epic showdown.
The climax arrives as the town prepares to defend themselves against Santana and his bandits, culminating in the destruction of a Sherman tank through sheer luck. Amidst the chaos, Larry heroically rescues Maria, the mayor's daughter, which leads to a kiss that sparks romance while additional U.S. troops finally arrive to apprehend the remaining insurgents.
Ultimately, the National Guardsmen emerge as unlikely heroes, receiving Silver Stars for their bravery, while Bill earns a Purple Heart from a comically unfortunate injury. Life takes surprising turns as Sergeant Kilgore relocates to Miami to start a private training camp, Everett finds fame as a Luchador called "Carne Asada" in Mexico, and Bill wins a settlement that moves him to Beverly Hills. Meanwhile, Larry returns to Mexico to marry Maria and opens a restaurant, "Larry's Mess Hall," in Cabo San Lucas, while Santana ends up in rehab, re-emerging as a ventriloquist, showcasing the unexpected outcomes of their wild adventure.
