At midnight on Dec. 23, 1948, the Japanese premier, Gen. Hideki Tojo, walked up the 13 steps to a wooden platform under a blaze of lights.

Ten minutes later he was dead, hanging from the end of 7-foot, 7-inch rope, a drop length precisely calculated to break the neck of the defeated Axis leader.Tojo had been sentenced to death by an international military tribunal under the auspices of American occupation forces.

Today many people are clamoring for the same fate for Saddam Hussein.

There are sound political reasons why we should not try Saddam. A weakened Saddam at the head of a functioning and unitary Iraq might be preferable to a martyred Saddam uniting discontented Arabs everywhere.

We can deal with any remaining threat to peace that he poses through deterrence, embargoes and regional security and disarmament agreements.

Indeed, we should go one step further and let him know now that we will not try him.

Leaving Saddam in power will frustrate many Americans.

Some Americans believe that in addition to venting our collective outrage at his murderous behavior, a war-crimes trial would set a precedent for how a new world order would handle leaders who step out of bounds.

To many, trying him seems not merely advisable but a moral imperative.

But such thinking represents a misunderstanding of the nature and history of war crimes trials.

We are not morally bound to stage them and should do so only if it is in our political self-interest.

War-crimes trials were conceived as a method of dispensing justice to combatants who violated the laws of war on the battlefield.

The Nuremberg and Tokyo trials marked the first time that a country's leaders were tried for the political decision to wage a war of aggression.

Yet Emperor Hirohito was not only spared a trial but left on his throne.

Allied generosity was not based on a belief that he was innocent, nor did the victors lack the power to try him.

Hirohito was saved by political expediency; the prospects for stability in a strategic region would have been threatened by an ungovernable Japan.

In general, trials for heads of state have been the exception rather than the rule. And unlike our criminal justice system, the decision to hold a war-crimes trial has borne little relationship to the magnitude of the crimes.

In addition to killers such as Stalin and Pol Pot, who escaped trial because they were never routed in battle, there are many aggressors, such as Napoleon and Kaiser Wilhelm, who were vanquished but not subjected to trial.

Is there is a moral imperative for trying Saddam that goes beyond our political self-interest?

Moral imperatives - dispensing justice to set a just precedent - require consistent application.

If we are acting under a moral imperative now, what imperative guided our policy of support for Saddam during the Iran-Iraq war?

What message do we send by trying him for crimes committed in a conflict with Western forces but ignoring (even supporting) his aggression when his opponents were non-Western?

Hypocrisy is a shaky foundation upon which to build a new world order, and America's own self-interest weighs against allowing frustration to dictate our policy.

If the tug of high-minded morality still whispers "try him," the realism of hardheaded politics says "don't."