MOST Americans are probably having a hard enough time trying to distinguish the good guys from the bad guys in Central America, and Oliver Stone's "Salvador" is careful not to help us take sides. Much to its credit, that's mainly what makes this political thriller so terrifying.

It's not that there aren't any villains in this film -- based on the real-life account of photo-journalist Richard Boyle who co-wrote the screenplay with Stone -- but that there are so few good guys to turn to.

James Woods easily slips into the role of Boyle, a sleazy unemployed journalist who convinces his out-of-work disc jockey buddy, Doctor Rock, that Guatemala is really the place they want to be "for fun, lots of girls, no laws, no cops and no yuppies." But Boyle tricks his beefy comic sidekick, played by Jim Belushi, into driving straight to El Salvador.

Boyle manages to become a stringer for some wire services and cable networks. A media veteran of Vietnam, Cambodia, the Middle East, Ireland and Central America, he's seen plenty of killing. But to the wisecracking Doctor Rock, the attacks on villages, the Death Squads of El Salvador's 1980-81 Civil War and the armless children are a revolting sight.

As he photographs gruesome dumping grounds for El Salvador's now-famous "missing," even Boyle slowly realizes that there is no clear-cut good side. That helpless feeling intensifies when four nuns are brutally raped and murdered and then pitched into a shallow grave.

Who's to blame for all this mindless violence? Everyone.

SALVADOR -- At the Circle MacArthur.