There are so many untold stories about the wars in Iraq and Afghanistan that the intentional implausibility of “The Lucky Ones” is truly cause for concern. Have we already given up on trying to transmit any shred of reality to the big screen? Is this all we have left to expect from our filmmakers — the ongoing wars reduced to prologue, used solely to add an air of gravitas to the most routine Hollywood melodrama?

Screenwriters Dirk Wittenborn and Neil Burger (the writer and director of the underrated “The Illusionist”) seem all too aware of the unprofitable fates of so many recent war-themed films. Their idea for bucking the trend? Throw a little of everything at the screen and see what sticks. In this story of a trio of Iraq war veterans who return from the battlefield to find that life has moved on without them, issues of divorce, college tuition, one-night stands, threesomes, airport closures, and tornadoes find their way into the drama.

In a mishmash of a concept that no one had yet thought of (with good reason), “The Lucky Ones” infuses the wartime mourning of “Grace Is Gone” with the road-trip camaraderie of “Little Miss Sunshine” and the unrelenting optimism of any title in the Frank Capra catalog. It’s a mess of a movie with a serious case of attention deficit disorder. One minute, a sobbing female veteran named Colee (Rachel McAdams) is consoled by two fellow servicemen, Cheever (Tim Robbins) and T.K. (Michael Peña), as she recalls the death of a comrade overseas. A few scenes later, her heartache has seemingly dissolved when she begins flirting with T.K. as they take cover in a ditch during a tornado. This is the same man who suffered a, er, groin injury in Iraq, and only a few moments earlier was nearly paired with a team of sex workers vacationing in a nearby park, in the hope of restarting his sexual apparatus.

Did we forget to mention that Colee also is carrying a guitar that once belonged to her fallen friend across the country? It’s a rare guitar, worth $20,000. Spoiler alert: That’s the same dollar amount that Cheever needs to put his son through college.

Those who love coincidence and happenstance might just consider “The Lucky Ones” the best film ever made. Messrs. Wittenborn and Burger clearly have set out with the noblest of intentions, aiming to relate the struggles that await our troops upon their homecoming, but the assembly is sloppy and, more often, silly.

Things even start on shaky ground. The older, chiseled Cheever is boarding a plane when he bumps into his two fellow soldiers as they all return home to the states following a deployment in Iraq. Together, the three troops make small talk. When they arrive at their connecting airport in New York, they are dismayed to learn that a blackout has forced the cancellation of all flights. So the three musketeers decide to rent a car and drive across the country.

It’s supposed to be a short-lived trip, terminating in St. Louis, where Cheever will return home to his wife and son, and where both T.K. and Colee will board flights to their final destinations. But within minutes of returning home, in a rushed scene of astonishing cruelty, Cheever’s wife has informed him that she no longer loves him, and his son has announced that he was accepted to Stanford and needs $20,000 to secure his spot. Not surprisingly, Cheever is distraught and, as he teeters on the brink of suicide, T.K. and Colee refuse to leave him behind. Instead, they decide to drive him to Salt Lake City, where his brother lives. Along the way, the three expose their inner and outer wounds with every passing mile.

One can easily imagine a different, better movie involving these three characters, one in which their attempts to deal with the issues of dead friends, lost loves, and battle scars would be used to far more poignant and powerful ends. In such a movie, their agony and loneliness won’t be minimized as fodder for a zany, whirligig road trip, complete with rural bar brawls and chance encounters with priests and prostitutes. The actors who get to star in that movie will truly be the lucky ones.

ssnyder@nysun.com