'ENGAGEMENT' BREAKS ITS OWN UNWRITTEN RULES.

Byline: Bob Strauss Film Critic

Withholding of evidence is a major plot point in ``Rules of Engagement,'' a military courtroom drama directed by William Friedkin and conceived by former Secretary of the Navy James Webb.

But the filmmakers commit something like the same crime as the film's civilian strawman. What we're shown in the early, action parts of the movie, and led to believe is the truth well into the picture's third act, turns out not to be the whole story. This makes for some rousing court- martial grandstanding and rah-rah support for the ``shoot first, question later'' approach to soldiering. But it betrays the more intriguing, complex examination of ethics under fire that the film promises for the longest time.

Superbly, if superficially, acted by Tommy Lee Jones, Samuel L. Jackson and Guy Pearce, and filmed with spit-and-polish precision, ``Rules'' is engaging as long as it refrains from taking sides in the case at hand. Once it sets to advocating, though, it loses us.

The opening sequence during the Vietnam War is nice and concise; it sets up personalities and relationships while not skimping on the terror and horror and the difficulty of decision-making under fire. Terry Childers (Jackson) and Hays Hodges (Jones) split their squad during a jungle engagement. Childers' operation succeeds and he takes a couple of North Vietnamese prisoners, but Hodges' command is wiped out and Childers resorts to extreme measures to rescue his wounded comrade.

Some 30 years later, Childers is a respected Marine combat colonel while Hodges, somewhat of a disappointment to his officer corps family and more than somewhat of a drunk, is about to retire from a mediocre career as a military attorney.

Then the folks over in the Arab nation of Yemen get upset about something. Childers heads a rescue mission to the besieged U.S. embassy there, where his men come under immediate and constant fire from snipers in nearby buildings. After taking several casualties, Childers gives orders to shoot into the crowd demonstrating in the street below. In the eerie quiet that follows, 83 local civilians, many of them women and children and all apparently unarmed, lie dead.

Quite understandably, the incident threatens U.S. relationships throughout the Middle East, and Childers must be scapegoated. Enter the bad civilian, a national security adviser played by Paramount Pictures' designated weasel, Bruce Greenwood (``Double Jeopardy''). Also, more formidably, a young bulldog prosecutor, Maj. Mark Briggs (Pearce, the fine Australian actor, affecting a perfect New York street brawler accent) is hot to purge the Corps of this trigger-happy vet.

Childers naturally turns for representation to the self-doubting man whose life he once saved. However, Hodges is not only limited by his own sense of inadequacy, but by the knowledge of to what lengths his dear but hotheaded friend is capable of going.

The early combat scenes have an immediacy and disorienting vividness that ranks right up there with prime Oliver Stone. The characters also exhibit potential early on; no one plays a loose cannon more intelligently than Jackson, and Jones is always at his best when playing against his naturally overconfident persona.

But as the film settles into rote, court-martial movie dynamics, it grows less engaging both personally and philosophically. Hodges does some key investigating on his own, Childers does the old Jack Nicholson blow-up on the stand, witnesses are pressured into lying, ``surprise'' testimony you knew was coming an hour earlier pops up at a climactic moment, and the few good men tell off the clueless desk jockeys but good.

And, of course, what we thought we saw happen is ultimately revealed to not quite have happened that way. Friedkin, an old master of movie trickery in his ``French Connection'' and ''Exorcist'' days, pulls it off with slick aplomb.

But it still leaves you feeling like you've been cheated by someone who hasn't played by the rules.

THE FACTS

--The film: ``Rules of Engagement'' (R; violence, language, children in jeopardy).

--The stars: Tommy Lee Jones, Samuel L. Jackson, Guy Pearce, Bruce Greenwood, Anne Archer, Ben Kingsley.

--Behind the scenes: Directed by William Friedkin. Written by James Webb and Stephen Gaghan. Produced by Richard D. Zanuck and Scott Rudin. Released by Paramount Pictures.

--Running time: Two hours, eight minutes.

--Playing: Citywide.

--Our rating: Three and one half stars.

CAPTION(S):

photo, box

Photo: Tommy Lee Jones, left, is a military attorney called upon to defend his longtime friend, played by Samuel L. Jackson, in ``Rules of Engagement.''

Box: THE FACTS (see text)