With the possible exceptions of Carrot Top and former Washington Bullets center Gheorghe Muresan, Arnold Schwarzenegger is undoubtedly the least likely person in the Western Hemisphere to blend in well in a South American country.

But this is one of many conveniences for which “Collateral Damage” asks us to suspend all rational thought. Among others, we must pretend that Arnold isn’t 10 years too old to be playing parts like this, that virtually every country south of the United States is perpetually in the grips of political strife and that half a city block in downtown LA being blown apart by a terrorist bombing is good exposition for a movie to have in today’s touchy clime.

Yes, this is one of the many films postponed by Sept. 11 that had the jingoist audacity to think that another steaming pile of Hollywood crap is exactly what America needs right now. But regardless of social context, a bad movie is a bad movie — and “Collateral Damage” is exactly that.

Schwarzenegger (“The 6th Day”) plays Gordy Brewer, a firefighter whose wife and son are incidentally killed in a terrorist attack on the Columbian embassy in Los Angeles. With nothing left to live for, Gordy begins to hatch a revenge plan, one that begins with him watching round-the-clock news coverage of the unspeakable violence that plagues the godforsaken jungles of Columbia.

Several leaps of logic later, Brewer is in Panama hiking to the Columbian border and speaking Spanish with as much willingness and fluidity as Archie Bunker. In his quest to find El Lobo, the sneering guerilla that stole his livelihood, Gordy is helped by a drunken mechanic (John Turturro, “The Big Lebowski”) and a chatty coke kingpin (John Leguizamo, “Moulin Rouge!”).

After infiltrating the guerilla camp and failing an assassination attempt, Gordy is rescued by CIA agents and brought back to American soil for the inevitable final showdown with El Lobo. You guess who triumphs in the end.

Arnold winces and grimaces his way through much of the performance, looking as though he’s waiting for a Chris Tucker-esque sidekick to quip witty remarks in between explosions. His career continues on its downward spiral, as he once again gets thrown into a haphazard collection of groan-inducing one-liners and action sequences that range from trite (a helicopter shootout — how novel!) to just flat out ridiculous (in one fight scene, he Mike Tysons a guerilla’s ear).

Director Andrew Davis (“The Fugitive”) keeps the film moving at a nice clip, but he couldn’t have been able to do much with something that was so obviously reworked and test-screened to death after Sept. 11.

There certainly were no Latin-Americans in those test-groups, as “Collateral Damage” goes out of its way to portray all native Columbians as either merciless terrorists or grinning, south-of-the-equator Uncle Toms. Hollywood will surely pump out more of this kind of emotional manipulation in coming months, and “Collateral Damage” provides another small sign at just how arduous America’s road to recovery is going to be.

Grade: D