The military justice system has never exactly enjoyed a great public image.

In films from Stanley Kubrick's Paths of Glory set in World War I, to the Australian Boer War masterpiece Breaker Morant, to the World War II drama The Caine Mutiny, the system has usually been portrayed as a tool of injustice, cynically used to protect the powerful by tormenting the powerless.

As the saying goes, "Military justice is to justice as military music is to music." Groucho Marx is credited with that though it might be best known as the title of a 1974 muckraking book by Robert Sherrill, yet another indictment of this mixture of military hierarchy and the judicial process.

This system is under scrutiny as it judges whether two Air Force pilots -- Majs. Harry Schmidt and William Umbach -- responsible for dropping a bomb that killed four Canadian soldiers in Afghanistan -- deserve to be court-martialed for criminal negligence and manslaughter. Their Section 32 hearing -- the equivalent of a grand jury proceeding -- ended late last week in Louisiana.

If the United States enters into another war with Iraq -- with pilots and soldiers and sailors unleashing unbelievable amounts of destructive force in increasingly complex technological battlefield arrangements -- the system will probably get an even closer look. In the 1981 gulf war, 35 of the 148 U.S. soldiers who died were killed by the same kind of "friendly fire" that killed the four Canadians.

Those familiar with the military justice system say that, despite its oft-tarnished public image, it actually works quite well.

"I know if I was going to be prosecuted on a charge against me, I would rather have it done in a court-martial than in the downtown court here in Durham," says Scott Silliman, director of the center for law, ethics and national security at the law school of Duke University in Durham, N.C.

Silliman and others argue that while the negative image might once have been accurate, a half-century of increasing professionalism has made the military justice system an admirable judicial institution.

Where once regular officers sat in judgment -- sometimes on trials that affected those they knew -- court-martial judges are now professionals whose military career has careers have been on a judicial track. The attorneys -- both prosecutors and defense -- are drawn from similar ranks.

"They are good prosecutors and good defense lawyers," says Abraham Dash, a professor at the University of Maryland School of Law.

"And it's not like in the old days when the court-martial board was set up by the commander, who could load it anyway he wanted. Now military judges come out of a separate category. They spend their career being military judges. When they sit as a judge they control the court-martial board," says Dash, a pilot in the Korean War who went on to a career as a military lawyer. "I'm not saying it's an ideal world, but it doesn't deserve the bad reputation it sometimes gets."

That goes for the rights of defendants as well.

"The military is more fair than the civilian system in the protection it affords the accused," says Benjamin Lucas, an adjunct professor at the University of Baltimore law school. He points out that the accused is entitled to a lawyer who can cross-examine witnesses at the Section 32 stage while civilian defendants have no such rights before grand juries.

Dash says the accused have other legal protections in the military.

"When I argue in defense of military justice, I remind many of my colleagues that way before the Miranda ruling required police officers to notify anyone taken into custody of his rights, the military was advising anyone the military police talked to about the right to remain silent," he says.

Perhaps most important, the possibility of someone pulling rank to influence a legal outcome has been diminished.

"It's called 'unlawful command influence' and it's a bugaboo in military justice," says Lucas, who spent 23 years as a military lawyer. "Senior commanders putting pressure on their juniors about a court-martial is one of the biggest concerns in military justice and they guard against it very carefully. Everyone is human, but I know the effort that is made. People go out of their way to avoid any indication of the appearance of impropriety."

Lucas says this was not always the case. "There was an unfortunate history of unlawful command influence, but in the last 30 years or so, the system has been working to negate that."

What can make this system appear opaque to outsiders is that it is not judging defendants according to civilian laws - it is looking at the application of military procedure. That is what is at stake in the current Section 32 proceeding about the deaths of the Canadian soldiers.

"I think the military justice system is very good at what it is designed to do, which is to maintain good order and discipline, something that is utterly different than what the civilian justice system does," says Michael F. Noone, a law professor at Catholic University who spent 20 years as an Air Force lawyer. "But in marginal cases like ones of negligent homicide, it is not better or worse than the civilian system."

No one says cases like this current one are among the toughest. "It is clear that the people accused of the crime were careless; the question is does that carelessness rise to the level of criminality?" He compares it to trying to decide if a fatal automobile accident deserves charges beyond traffic violations.

In this case, there seems to be little doubt that there was, if not complete ignorance, at least some confusion about the presence of the Canadian troops in the area that these planes were patrolling. Weapons were fired beneath the planes. The pilots say they thought they were being fired on. It turned out to be Canadians practicing.

What is in contention is what the pilots did next. Saying he was acting to defend Umbach and his aircraft, Schmidt took his F-16 from 15,000 to 10,000 feet and dropped a laser-guided 500-pound bomb on the Canadians. Military prosecutors say that violated procedures which called for the pilots, seeing the ground fire, to climb out of danger and fly away, especially with words of caution coming from their controlling officer.

"The rules of engagement for these missions when dealing with a threat [of anti-aircraft fire] below you say to accelerate and climb out," says Silliman, who spent 25 years as an attorney in the Air Force before joining the Duke faculty a decade ago. "Basically they were not threatened at that altitude. ... That's why you have to have rules of engagement to deal with unusual situations, which this was."

But ex-combat pilot Lucas argues that those rules are out the window if you feel threatened. "It is a split-second decision in many cases, if you think you are being shot at," he says. "You don't have the luxury of second-guessing."

Dash agrees. "Most rules of engagement for as long as I remember say that if I felt I was in danger, I could disregard the controller. The issue here is, were they in danger?"

The fact that the pilots were given amphetamines by the Air Force - an issue raised by their attorneys as a possible reason for their clouded judgment - is seen by some as irrelevant.

"I don't think it is much of a defense - I think it's kind of stupid," says Dash, who notes that he and his crews were regularly given Benzedrine during the Korean War for lengthy night missions.

Silliman emphasizes that no procedures will stop such incidents. "In an armed conflict, you accept accidents. You accept the Navy pilot in Afghanistan who mistakenly dialed in the wrong coordinates on a bomb. If your intelligence is bad, as it was in Afghanistan, you end up using an AC-130 on a wedding party because you didn't know it was a wedding party."

And that raises another question - would there have been the possibility of prosecution if these pilots had killed a few Afghan civilians, not troops from Canada? The latter country suffered its first combat losses since the Korean War, generating huge amounts of publicity.

The experts say that even if Afghan civilians had been the victims, there certainly would have been an investigation, perhaps even a court-martial.

"The fact that these were coalition forces probably had something to do with this thing moving forward," Lucas says. "But all situations are investigated."

Silliman says there were courts-martial of soldiers for using too much force when U.S. troops went into Panama. "You didn't hear too much about that."

Certainly the military justice system can be affected by political pressure, but, they argue, that is no different than the civilian judicial system.

"To me, an elected prosecutor is under more undue pressure than today's average military prosecutor," says Dash.