London

GEORGE ORWELL is usually a footsure guide across political battlegrounds. In late 1943, when the tide had turned in the Allies’ favor, he wrote about postwar trials. Oddly, he advocated Hitler and Mussolini slipping away. His verdict for them would not be death unless the Germans and Italians themselves carried out summary executions (as they eventually did in Mussolini’s case).

He wanted “no martyrizing, no St. Helena business.” Above all, he disdained the idea of a “solemn hypocritical ‘trial of war criminals,’ with all the slow cruel pageantry of the law, which after a lapse of time has so strange a way of focusing a romantic light on the accused and turning a scoundrel into a hero.”

For once Orwell missed his step. The Allies did stage a trial of the Nazi war criminals, at Nuremberg. (My father, Hartley, was the chief British prosecutor.) The trial had flaws. To some it will always seem to be “victors’ justice” and it can be called hypocritical in that the Soviet Union, guilty of many of its own crimes against humanity, was an equal partner with the democratic prosecutors and judges.

But, over all, it succeeded very well. It was solemn, as it should have been, and what Orwell called “the pageantry of the law” was neither cruel nor slow — the trial began in November 1945 (remarkably this was only six months after the German surrender) and was all over by the following October. Would that anything could be done so efficiently today.

Most of the Nazi defendants were found guilty and executed, others were given lesser sentences and some were acquitted. Orwell’s fear that they would later be cast in a romantic light and turned from scoundrels into heroes has not been realized. They are still seen as mass murderers.

Nuremberg not only dispatched justice swiftly, it also created a historical narrative that has survived. Robert H. Jackson, the chief American prosecutor and the driving force behind the trials, told President Harry S. Truman that he had assembled more than five million pages of evidence. The files of the SS alone needed six freight cars to carry them. Subsequently the tribunal published 11 volumes of documents and 20 volumes devoted to the proceedings alone. The eminent British historian Alan Bullock wrote of his excitement at reading through these records: whatever the arguments about justice, “from the point of view of the historian the Nuremberg trials were an absolutely unqualified wonder.” Nuremberg was essential in creating memory and senses of responsibility, in Germany itself and far beyond.

Nuremberg, lest we forget, was a military tribunal with civilian lawyers and it offered far fewer protections to the Nazis in the dock than the military commissions at Guantánamo will give to Khalid Shaikh Mohammed and his co-defendants in the 9/11 attacks. Military justice worked then and it can work again today.

This is not the place to repeat the fierce disputes over President Obama’s decision last week to prosecute Mr. Mohammed before a military commission instead of a civilian court. What they show above all is that there are no absolute truths; law is argument.

Many of the important Supreme Court decisions in the war on terrorism have been made by slim majorities, one way or another. In such complicated areas it is rare to find unanimity. This is not surprising. Indeed, such debate is a token of the vitality of American jurisprudence.

I understand why many people believe that in the hugely important, and hugely symbolic, case of Khalid Shaikh Mohammed, America would be best served by justice being dispensed in an open federal court. But United States military law should not be dismissed. It has a distinguished history dating back to 1775; every year military courts dispense justice to thousands of Americans. And don’t forget that the Qaeda detainees in Guantánamo will all be presumed innocent, their guilt must be proved beyond reasonable doubt, and each will have the right of appeal all the way to the Supreme Court.

As far as Al Qaeda and its associates are concerned, it does not make the slightest difference whether its members are tried in federal or military courts — Islamists regard each as equally illegitimate. As Anwar al-Awlaki, one of Al Qaeda’s most prominent ideologues today, has said, Muslims must not be forced to accept the rulings of Western courts; he insists that for Muslims to abide by Western laws is to live like sheep “stripped from their right to live as Muslims under the law of Islam.”

No form of Western justice will ever be accepted by Al Qaeda. But President Obama could seek to make trials in Guantánamo more accessible to the rest of the world. One should never forget that most of the people killed by Al Qaeda around the world are not Americans — the majority are innocent Muslims caught up in Islamist killing sprees in Iraq, Pakistan, Afghanistan, Somalia and elsewhere.

Even on Sept. 11, hundreds of those killed were non-Americans. Britain lost 67 people that day. Their families, too, have an interest in seeing justice done. They could also assist.

The United States is well practiced at military officer exchanges. Why not invite those nations with a jurisdictional claim against Mr. Mohammed — those which lost citizens on 9/11 — to send cleared and qualified senior military lawyers to serve in the court at Guantánamo? This could be done after Congressional modification of the 2009 Military Commissions Act to determine in what roles they could serve. Britain, Japan and Ghana are three countries that could qualify.

Such internationalization of the court in Guantánamo would call the bluff of those American allies who benefit from American protection but cannot resist criticizing its processes. It would not be precisely modeled on the successful tribunal at Nuremberg, but it would follow in that hybrid tradition of using the best civilian and military advocates, prosecutors and processes all carrying out their tasks in the full view of the press.

The trial of Khalid Shaikh Mohammed and his co-defendants is of vital significance because it addresses not just a group of thugs but the enduring human phenomenon of evil. No two eras are the same, nor are the threats they face identical. But evil is eternal and re-invents itself in every age.

In the 1940s the world confronted and, with immense sacrifice, defeated the evil of fascism. The scale and the nature of the threat is different today but true menace — from the attacks of 9/11 itself to the recent beheading of United Nations workers in Afghanistan simply because a Koran was burned in Florida — lurks patient and opportunistic. It cannot be appeased any more than Hitler could be appeased.

Despite Orwell’s misgivings, at Nuremberg our civilization designed a vehicle to anathemize men imbued with evil. And it created a historical narrative that proved invaluable throughout the decades since. The case against Khalid Shaikh Mohammed and his friends must develop a similar, vital history of Al Qaeda to inform generations to come. Nuremberg is a precedent on which the United States can build with pride in this new and essential trial.