Unlike most tribunals, a military court does not explain its judgments. The long full trial proceedings in the case of Lieutenant William Calley left no room for doubt that he did in fact kill many unresisting Vietnamese villagers at My Lai 4, or Son My, or whatever the place is rightly called, when he was an infantry platoon commander three years ago. The number of victims could be, and was, disputed. The charge sheet had at least 102 men, women and children; the jury amended the figure to not less than 22. Mr Calley's defence never denied the killing, but maintained that it had been done under orders and in the belief that it was what his military duty required of him.

Either the jury made a conclusion of fact, that Mr Calley did not receive the orders he claimed, or it made a conclusion of law, that the orders were wrongful and should have been disobeyed. However, it did not have to say which of the two paths it took to arrive at the verdict, guilty of pre-meditated murder, pronounced on Monday, and at the sentence, life imprisonment. At some point, perhaps, the series of appeals which are promised by Mr Calley's defence lawyer will escape from the reticence of the military process into the relative light of the civilian courts. Certainly the rising legal and academic clamour about the rules of war as they have been applied in Vietnam will not leave the case alone.

There was a time when eminent lawyers like the late Thurman Arnold defended President Johnson's intervention in Vietnam as “the enforcement of the principle that Nuremberg announced to the world.” That principle was the criminality of aggressive war. But the Nuremberg and Tokyo tribunals of a quarter of a century ago also stated other principles—for instance, that responsibility for the manner in which war was conducted rested most heavily upon the commanders at the top. As the American prosecutor said in United States versus Von Leeb, “mitigation should be reserved for those upon whom superior orders are pressed down.” General Yamashita was hanged, after due process, for his failure to prevent the cruelties committed by his far-flung army. The Nuremberg prosecutor, General (now Professor) Telford Taylor, brooded on these memories in a recent scholarly book, “Nuremberg and Vietnam.” He concluded that the series of courts martial arising out of the Son My or My Lai massacre “cannot be fairly determined without full inquiry into the higher responsibilities” and that the moral health of the American Army will not be recovered until its leaders are willing to scrutinise their behaviour by the same standards that their revered predecessors applied to Yamashita 25 years ago.

It was the late General MacArthur who confirmed the death sentence on Yamashita. The scale of the uproar that has built up around these and related questions is illustrated by the bibliography of 33 book titles published last weekend by the New York Times Book Review, together with a vast review by a former war correspondent in Vietnam, Mr Neil Sheehan, demanding a general congressional inquiry into war crimes.

This does not stop Mr Calley getting a lot of sympathy in his misfortune. The inevitable stream of telegrams protesting against the verdict is pouring into the White House, the Defence Department and Congress. Two themes mark the protests: one that a dim junior officer is being made to bear guilt that belongs much higher up; the other, that what he did was in the nature of war and that the soldier's life is made impossible if his actions in the stress of battle are to be picked over and dissected afterwards by lawyers and officials.

In some ways the wave of sympathy distorts the facts. Since nearly six years and millions of words of news reporting have failed to disclose any other massacre by American troops on anything like the scale of Son My, the probability that Son My was in fact an extraordinary occurrence looks overwhelming. Whether Mr Calley understood that anything extraordinary had been done or not, the behaviour of many of the other people concerned—those who refused to join in, those who hushed it up and those who eventually talked—suggests that they knew it.

But Son My was also out of the ordinary in another way, as Professor Taylor says, in the candour with which the operation was carried on, with army photographers on the scene and commanders in helicopters circling overhead.

Considering all this, the performance of the Department of the Army in finding out what happened and deciding what judicial steps to take was unbelievably sluggish. A first investigation in 1968 was defeated by the bland denials of the brigade and divisional authorities. After the story had all come out in the press a senior general investigated the reason for the collapse of the first investigation.

He did his job thoroughly and as a result 14 officers were accused of various degrees of lying, concealment and failure to follow staff regulations. But the charges have been dropped or dismissed against all but one, the brigade commander. General Westmoreland, the Army's Chief of Staff, has recommended that the divisional general at the time be demoted to brigadier-general and that his assistant commander should be demoted from brigadier-general to colonel. The demotions, if they go through, are punishments. As the New York Times commented this week, “if the two officers are innocent, obviously they should not be punished.” Nobody has tried to explain how, if their part in the concealment of the massacre deserves to be punished at all, it can be adequately punished by demotion to brigadier-general and colonel.

One thing that is totally impossible is that Mr Calley alone is guilty. But, leaving aside the brigade commander who is charged with failing to tell what happened, only two men besides Mr Calley are at present faced with charges of having had a part in the massacre. Mr Calley's company commander, Captain Medina, who denied having given him orders to kill off the population, is charged with murder. Another officer of the task force, Captain Kotouc, is charged with maiming and assault. A warrant officer and a sergeant were accused of murder and acquitted. Charges against six other soldiers in Captain Medina's company have been dropped. Others had left the service by the time the fact of the massacre became public and the legal problem of bringing any of them to justice has not been solved.

Granted that Son My was not a usual event, it would still seem that the war has calloused a lot of consciences. The trial proceedings themselves, with their emphasis on the preponderance of women, children and infirm old men among the victims, gave evidence of how standards have slipped; nor is there anything in the accepted rules of war to justify the unnecessary killing of unarmed, unresisting men, however able-bodied. But the Vietcong do not exactly observe the provision of the Geneva Convention which says that a combatant must wear “a fixed distinctive sign recognisable at a distance.” Thus it has become commonplace in Vietnam for people to be treated as enemies even if they are not carrying arms and are not dressed, and are not seen to behave, like soldiers. Even women and children can, and sometimes do, plant booby-traps.

In the words of an American Air Force major, “in the mountains, just about anything that moves is considered to be Vietcong.” Son My is not in the mountains but it is in an old communist area and Lieutenant Calley's platoon, men of limited intellectual equipment in a state of nervous tension, entered it believing that every living thing was hostile. This does not justify what they did. They were, however, familiar with the practice by which villages and hamlets are routinely threatened with destruction with bombs or gunfire, as a penalty for having harboured the Vietcong, and with the doctrine of free fire or free strike zones, which orders the removal of the rural population from an area so that any persons remaining in it may, if sighted, be killed. Success in operations of this kind tends to be measured by the “body count,” a standard of military effectiveness which would be laughable if it were not sad.

Last year the trial of Lieutenant Duffy brought out the importance of the body count. Mr Duffy, it is not disputed, had a prisoner tied securely to a stake and when morning came had one of his sergeants shoot the man dead. At his trial Mr Duffy explained that his superiors expected, indeed insisted upon, a good body count and soldiers who turned in live prisoners were apt to encounter official disapproval. The curious thing about Mr Duffy's trial was that the military court revised its first verdict of murder, between judgment and sentencing, substituted a new verdict, of “involuntary manslaughter” and gave him only six months. Whatever else could be said of Mr Duffy's action, there was manifestly nothing involuntary about it. Court martial watchers concluded, therefore, that the court felt there was something in his contention that he thought he was only conforming to established policy and that it found in this a mitigating circumstance.

Aberrations like this in the observance of the rules of war may be liable to creep in as a result of some tactical brainwave or quirk of military bureaucracy but, once they are examined and brought to light, it is impossible for the American Army and the American Administration to do anything but disavow them and try to put them down. That the Vietcong and the North Vietnamese do worse things, and on a bigger scale, may be true but, as an argument, it is no help at all. Thus, while President Nixon exposed himself to censure for an indiscretion when he condemned the “massacre” at Son My at a time when judicial proceedings were pending, he could never have contemplated doing other than condemn it.

Similarly the Army as an institution cannot defend or explain or condone: if a side-effect of the callousing process that is inflicted upon American servicemen in Vietnam comes to its attention, it has to express its condemnation in the obvious way, by prosecuting the transgressors. In pressing for criminal convictions against Mr Duffy and Mr Calley, the army authorities were seeking to rebut the charge that inhuman actions are a consequence inherent in their strategic or tactical doctrines or in the use of military force itself as a political instrument. This they have to do in defence of not only the propriety of their policies, but also the legitimacy of the Army itself.