Before​ examining the most notorious war crime of the Vietnam era, it seems useful to glance at some other modern horror stories. At 2.15 p.m. on the afternoon of 10 June 1944, a company of the 2nd SS panzer division, ‘Das Reich’, entered the small French town of Oradour-sur-Glane, herded most of its population, swollen by refugees, into barns and garages, the women and children into the church, then killed them with firearms and grenades. The panzergrenadiers had been informed that Oradour was a hotbed of Resistance activity and were seeking revenge for the abduction nearby, on the previous evening, of a popular battalion commander. The regimental war diary recorded, entirely mendaciously, that Resistance arms and ammunition had been found in almost every house. A situation report to divisional headquarters announced 548 ‘enemy dead’. The true figure appears to have been 642, all of whom were innocent civilians. When a stunned parent reached Oradour late that afternoon, found the place deserted and asked where all the children were, a German responded succinctly: ‘Alles kaputt.’ In 1980 a German veteran whom I interviewed for a book told me of a conversation about the massacre with one of those who carried it out, who said confidingly: ‘Speaking as one old SS man to another, Herr Muller, it was nothing. In Russia, we did such things every day.’

The 1953 trial in Bordeaux of 21 of those who carried out the Oradour killings proved an acute embarrassment for France, still traumatised by its experience of occupation. Fourteen of the accused proved to be Alsatians – French citizens. Following their convictions, all but one were quickly amnestied by the Paris government. Its attitude may have been influenced by the fact that the French army had carried out many more recent mass killings of civilians in the course of suppressing revolts in Algeria (1945) and Madagascar (1947), and was even then committing massacres in Indochina, still a French colony.

The British army for years sustained a legend that it achieved success in its colonial ‘brushfire wars’ through the efforts of kindly Tommies in winning hearts and minds. Recent studies – for instance, David French’s excellent The British Way in Counter-Insurgency 1945-67 – show that in Malaya, Cyprus, Aden and Kenya British soldiers in fact displayed frequent brutality, often condoned by their officers. In all of Britain’s counterinsurgency campaigns, especially in Kenya, substantial numbers of unlawful killings of civilians took place, even if there is no credible evidence of anything on the scale of My Lai.

We may go further, and notice that during and after the Second World War, scarcely any Allied soldiers, sailors or airmen were prosecuted for war crimes, though there was ample evidence to support charges, had there been the will to pursue them. SS prisoners, for example, were frequently shot out of hand. There was at least one large-scale killing of German PoWs on the Canadian front in Normandy. I have interviewed many former Allied fighter pilots who admitted to deliberately strafing – killing with cannon, rockets and bombs – civilians in Germany during the relatively carefree days just before the war ended.

My point is not to suggest that the American soldiers who committed the My Lai massacre behaved no worse than British or French soldiers in similar circumstances; or even that the US army should be compared institutionally with the Waffen SS, which it certainly should not. It is to remind ourselves that the unique selling-point of soldiers, even if tarted up in fancy-dress uniforms and bearskins, is that they are trained killers.

It is a constant challenge for leaders on the battlefield to ensure that the young men carrying lethal weapons under their command shoot the right people and do not shoot the wrong ones. In all armies, control and disciplined restraint are sometimes lost. Soldiers who participate in armed conflict emerge morally compromised – how could they not, when they have been killing their fellow man? Veterans and historians alike must simply debate in what degree a given army at a given time and place has dirtied its hands.

It deserves notice that the communists murdered in cold blood far more innocent people during their February 1968 occupation of Hue than the My Lai killers did. The Vietcong were merely smart enough not to allow their massacres – or their frequent disembowellings and live burials of village chiefs who declined to support them – to be recorded on camera, as My Lai was, or to become the object of war crimes trials. A majority of American soldiers completed tours of Vietnam without being party to atrocities, but to understand My Lai, it is necessary to recognise that in the US army in Vietnam in 1968, a culture of cruelty was prevalent. While writing my own narrative of the war, I have interviewed many veterans: the anecdotes I will include here provide some context for the subsequent doings of Lieutenant William Calley and his comrades.

Adviser Mike Sutton one day landed in a Huey helicopter in a Delta hamlet where a limp figure was hanging from ropes lashed to a tree – the village chief, disembowelled during the night by Vietcong guerrillas. His wife had been less artistically murdered, their son castrated. ‘I thought: “What barbarians.” But then later I saw Americans do some terrible things too.’

Phil Caputo, one of the first Marines to land in Vietnam in 1965, was dismayed to discover that not all the members of his platoon, in which he took such pride, had a store of humanity as impressive as their combat skills. ‘Some of them were not so decent and good,’ he wrote in his classic combat memoir, A Rumour of War. ‘Many had petty jealousies, hatreds and prejudices. And an arrogance tempered their ingrained American idealism.’ His sergeant observed that during the Korean War, he had seen men sight in their rifles by firing at farmers: ‘Before you leave here, sir, you’re going to learn that one of the most brutal things in the world is your average 19-year-old American boy.’

He was thinking of men like Lance Corporal Marion McGhee, a fireteam leader in the 3/3rd Marines, who on 12 August 1965 walked out of the unit perimeter announcing that he was ‘going after a VC’. Two men sent in pursuit heard a shot and a scream, then met McGhee walking calmly towards them. He said he had just killed a VC, and was going back for more. It was later established that he had kicked through the wall of a hut in which a family was sleeping, seized a 14-year-old girl and shot dead her father when he sought to intervene. At his subsequent court martial he offered a defence of insanity – the usual plea in scores of such cases during the years that followed – but was eventually found guilty of unpremeditated murder, for which he served six years’ imprisonment.

One day in 1966 a Marine battalion medical officer arrived at a firebase, took aside its commander, Captain Walt Boomer, and warned him that his company was collecting the ears of dead enemy soldiers as souvenirs. Boomer gathered the men that night, sat them down and said: ‘If you ever do this again I’ll kill you. What would your mothers say?’ The captain, who ended his career as commandant of the Marine Corps, believed tough leadership was the only way to check excesses: ‘From cutting off ears you can spiral into terrible atrocities. My Lai happened because officers failed.’

Another Marine, Captain John McNamara, wrote home in 1967 that he was appalled by the loose talk he heard among his fellow officers about the need to employ terrorist tactics against terrorists: ‘Just a few years ago it was confined to the fringe. If the actual [US military] establishment ever starts going that way – good grief. The thing is really about leadership, because quite decent people become frustrated … Beware the wrath of the centurions.’

‘The only thing they told us about the Vietcong was they were gooks,’ army private Reg Edwards said. ‘They were to be killed. Nobody sits around and gives you their historical and cultural background. They’re the enemy. Kill, kill, kill.’ At 7 p.m. on 23 September 1966 a nine-man ambush patrol from 1/5th Marines set out from Hill 22, north-west of Chu Lai. It was nominally led by Sergeant Ronald Vogel, but an aggressive 20-year-old combat veteran, Private John Potter, announced he was assuming command: the mission would be a ‘raid’. Every man was told to remove his unit insignia, and not to refer to each other audibly by name. In a nearby hamlet, they seized a peasant, accused him of being a Vietcong, and began beating him. Four other men dragged his wife out of their hut, pulled her three-year-old child out of her arms, then raped her. The patrol next shot her husband, child, sister-in-law and sister-in-law’s child. Potter tossed a grenade at the bodies ‘to make it look good’. Finally the Marines shot the rape victim and left her for dead.

The story gets worse. When the Marines returned to base and their company commander ordered an investigation of this alleged ‘enemy contact’, an officer went back to the scene and directed attempts to hide the truth. During this process a badly wounded child was spotted, whom Potter clubbed to death with a rifle butt. The facts emerged only when the rape victim was found alive by fellow villagers and carried to the Marine base for treatment. She told her story, which a medical officer immediately reported. Potter served 12 years for premeditated murder and rape. The officer responsible for the attempted cover-up was sentenced to be dismissed from the Marines, but the verdict was overturned on appeal: only two other patrol members served significant prison sentences.

In a typical two-week search-and-destroy operation in August 1967, codenamed Operation Benton, soldiers of Task Force Oregon destroyed the homes of more than ten thousand Vietnamese. In an area just six miles by 13, US forces dropped 282 tons of bombs and 116 tons of napalm. Fixed-wing aircraft fired more than a thousand rockets, 132,820 rounds of 20mm cannon ammunition and 119,350 7.62mm rounds, while artillery fired 8488 rounds. Around 640 refugees were evacuated to government camps. Commanders declared an enemy body count of 397, but it is unlikely that anything like that number were communists bearing arms.

Staff-Sergeant Bob Destatte had a Vietnamese wife and spoke the language fluently. While serving as a PoW interrogator, he formed a close relationship with Le Van Hiet, his detachment’s interpreter. One day in January 1967, in the midst of Operation Cedar Falls in the Iron Triangle area north of Saigon, Le came to him ashen and in tears, muttering that two captains from an armoured cavalry unit had just kicked a prisoner to death, a boy who had carried the electrical battery for the bullhorn used by a VC armed propaganda team. French soldiers had killed Le’s own peasant father in the same fashion. Destatte went to investigate, and found the brigade surgeon in a rage, having examined the body and found the allegation true. ‘If I had time and facilities to conduct an autopsy, these guys would go to jail,’ the doctor said. As it was, the officers lied – and went free.

The overwhelming majority of US forces felt a cultural disdain for Vietnam’s inhabitants. Draftee Don Graham, the son of the owner of the Washington Post, spoke of ‘the unanimous feeling of contempt for Vietnamese soldiers among Americans’. ‘I saw men who behaved with great compassion towards the Vietnamese one day,’ Phil Caputo wrote, ‘and then burned down a village the next.’ One peasant girl, Phung Thi Le Ly, who served as cook for a Danang hooker, remembered that what she feared most ‘were the Marines in fatigues who sometimes stopped by on their way from the field – smelling like water buffalo, unshaven, with weapons and the reflection of death in their eyes. To me they were as terrible as the “slash-faced” Moroccans who loomed out of the trees like giants 13 years before.’

A foreign service officer named Doug Ramsey said that during his own terrible seven-year jungle imprisonment by the Vietcong ‘my worst moment was when I was taken into a hamlet that the Americans had just worked over’ – and utterly destroyed. ‘The hamlet chief said: “Here is your American aid.”’ Some senior officers were sensitive to the damage done to their cause by murdering civilians. They nonetheless gave much less attention than they should have done to lesser sorrows inflicted by careless soldiers: peasants doused in mud by passing trucks, rice crops poisoned by waste water from nearby US bases, drying washing browned by dustclouds created by low-flying helicopters. When the 101st Airborne division established its base, Camp Eagle, bulldozers casually destroyed thirty family graves outside the neighbouring village.

Frank Scotton, a civilian field officer for the United States Information Agency who gained a deep knowledge of Vietnam and its people, wrote about the average grunt’s attitude: ‘By a peculiar syllogism (people like us don’t live like animals; Vietnamese live like animals: therefore, they aren’t people) Vietnamese were too often considered subhuman. Only a rare American combatant recognised the sophistication of Vietnamese culture and its relationship to the environment and concluded: “We were the gooks.”’ Major George Bonville was dismayed by the excesses of some Americans, one of them in his own team:

Old papa-sans were getting killed by ambushes or patrols for just getting up in the dark of night and wandering out of their huts to take a leak. When a child might get very ill and the mother was terribly concerned, she might light a torch and try to carry the child across rice paddies to the clinic … In one case the torch blew out and unknowingly, a US ambush took the family under fire as they were coming out of a contested hamlet. The mother was wounded and the child died. What a hell of a war I was involved in.

And so​ to My Lai, the subject of this authoritative new account by Howard Jones. The ghastly story burst on the world on 12 November 1969, when Associated Press wires carried the first report by the freelance investigator Seymour Hersh indicating that men of the 23rd Americal Division had carried out a massacre of civilians at My Lai, a few miles from the sea in Quang Ngai province, and that some officers were to face courts martial. During the months and years that followed, it emerged that on 16 March 1968 at least 504 peasants of all ages and both sexes had been murdered without the slightest provocation by C Company, 1/20th Infantry, most of them in a hamlet properly called Tu Cung, and designated by the army My Lai 4.

Far from representing a momentary homicidal impulse by one man or a small group of men, the killings proved to have continued over several hours, and at least forty of C Company’s 105 men participated. None made any attempt to stop others killing villagers, or gang-raping women before murdering them. ‘I just lost all sense of direction, of purpose,’ one soldier, Varnado Simpson, said later. ‘I just started killing in any kind of way I could kill. I didn’t know I had it in me.’ One of the first of those he shot was a child; after that, he said, ‘My whole mind just went.’

My Lai lay in Pinkville – an area dominated by the communists. Before launching C Company on its sweep of the area that day, commanders informed officers and men that they should assume everybody they met was an enemy sympathiser, if not a guerrilla. Throughout the battalion, and indeed throughout the Americal, casual violence towards civilians was indulged. Captain Ernest Medina, commanding C Company, had earlier ordered the shooting in cold blood of two fishermen, and men of the unit had murdered other civilians without incurring censure. Rapists were not subjected to disciplinary action.

On 14 March a patrol of C Company had triggered a booby trap that killed two men, tore the legs off two more and injured another two. Soon afterwards, soldiers angry at the casualties saw a woman working in the fields. Private Greg Olsen, a Mormon, wrote to his father describing what happened:

They shot and wounded her. Then they kicked her to death and emptied their magazines in her head. They slugged every little kid they came across. Why in God’s name does this have to happen? These are all seemingly normal guys; some were friends of mine. For a while they were like wild animals. It was murder, and I’m ashamed of myself for not trying to do anything about it. This isn’t the first time, Dad. I’ve seen it many times before.

The day before the massacre, Chaplain Carl Creswell attended a divisional briefing at which a major set the mood for the impending sweep by saying: ‘We’re going in there and if we get one round out of there we’re going to level it.’ ‘You know, I didn’t really think we made war that way,’ Creswell said fastidiously. The major shrugged: ‘It’s a tough war, chaplain.’

During the months following My Lai, there was an institutionalised cover-up. Commanders ignored a vivid report made by a helicopter pilot called Hugh Thompson, one of a tiny handful of those involved who behaved honourably and courageously. Thompson raised hell about what he saw, and kept raising hell thereafter. Nobody wanted to hear: two army chaplains were among those who should have faced courts martial – as they did not – for failing to report the ghastly tale Thompson told them.

The task force’s commander, Lieutenant Colonel Frank Barker, dismissed reports of an atrocity, brushing aside the implausibility of the 1/20th Infantry’s initial claims to have killed 128 enemy combatants while not recovering a single weapon. ‘It was tragic that we killed these women and children,’ he said, ‘but it was in a combat situation.’ As evidence mounted of the heinous nature of what had been done, Barker’s lies became ever more obvious, until a month later he spared himself further embarrassment by dying in a helicopter crash.

The consistent behaviour of all the officers in the chain of command, and later by officers in Washington, helped dismiss claims of a major war crime for many months. In March 1969 Ronald Ridenhour, a helicopter door-gunner, wrote to thirty members of Congress, describing atrocities – My Lai was only the foremost – that he had heard described in vivid detail by those who had participated in them. Private Tom Glen, a 21-year-old from Tucson, who served in another brigade of the Americal, wrote a brave letter to the US army’s commander-in-chief, Creighton Abrams, describing the dreadful deeds that he had been told other units in his division had committed.

In response, 23rd Division staff officer Major Colin Powell, later the US secretary of state, produced a memorandum for the adjutant-general which was an uncompromising whitewash: ‘Although there may be isolated cases of mistreatment of civilians and POWs this by no means reflects the general attitude throughout the division. In direct refutation of this portrayal is the fact that relations between Americal soldiers and the Vietnamese people are excellent.’ Powell did not interview Glen, arguing that since he hadn’t been an eyewitness, he had nothing to contribute.

The inquiries into My Lai produced evidence of another atrocity committed in the same period by Bravo Company of 4/3rd Infantry, for which no one was ever convicted. The 23rd Division’s commander, Major General Samuel Koster, acted ruthlessly to frustrate proper inquiries. When Lieutenant General William Peers conducted a belated but full investigation in November 1969, he accused 28 officers, including two general officers and three colonels, of 224 serious military offences, ranging from false testimony and failure to report war crimes to conspiring to suppress information, participation in or failure to prevent war crimes.

Just one man was eventually convicted and imprisoned: the 1st platoon commander, Lieutenant William Calley. The evidence was overwhelming that Calley, whom one soldier characterised as ‘an inadequate little guy, sick of being pushed around’, personally killed groups of villagers, and directed others in doing so. Yet his apologists insisted that, among so much blood and so many guilty men, he was scapegoated. When Captain Ernest Medina was acquitted of the charges he faced, the presiding judge wished him a happy birthday. The five thousand telegrams sent to the White House about Calley’s conviction on 29 March 1971 ran a hundred to one in his support, and the national commander of the Veterans of Foreign Wars complained that ‘for the first time in our history we have tried a soldier for performing his duty.’ A 1969 Time magazine poll showed that 69 per cent of Americans believed that ‘things like that happen in time of war.’ President Nixon exclaimed repeatedly to a White House aide in November 1969, as the New York Times headlined the My Lai story, that ‘it’s those dirty rotten Jews from New York who are behind it.’ Recruits marching at Fort Benning chanted: ‘Calley … Calley … He’s our man.’ AFN Saigon repeatedly played a ballad recorded by an Alabama group: ‘My name is William Calley, I’m a soldier of this land/I’ve vowed to do my duty and to gain the upper hand,/But they’ve made me out a villain/they have stamped me with a brand.’ MACV eventually ordered the radio station to stop playing the disc, which sold 200,000 copies, but could not suppress grunt graffiti in Saigon: ‘Kill a gook for Calley.’ Calley was eventually paroled at the direction of the secretary of the army in September 1974, after serving a sentence of just 42 months’ confinement to his quarters.

The​ My Lai massacre has come to symbolise all that was worst about the US armed forces’ conduct of the war. The lieutenant stretched the truth when he asserted that he was ‘just following orders’, but he could legitimately assert that the killings reflected a culture of casual murder, a racial contempt for Vietnamese, which infected many US units and their commanders. Even when a belated judicial process began, it fell to pieces amid the rival demands of anti-war sentiment, politics and supposed patriotism. The army would have struggled to punish all the men in the 23rd Division who breached the laws of war and of human rights: such a course would have required the imprisonment of scores of officers and men. But justice would have been well served by imposing custodial sentences on several of the senior officers named by the Peers inquiry, Major General Koster foremost among them.

More than a few American officers recalled that after the end of the Second World War, the US army hanged General Tomoyuki Yamashita, holding him culpable for atrocities committed in the Philippines by his soldiers. It was acknowledged that Yamashita had neither ordered the crimes, nor even perhaps known of them. But the court found that he should have done. Koster’s case was worse, in that there was no dispute about his knowledge of the crime or his wilful deceit in seeking to suppress the facts about it. Yet Koster was permitted to remain a serving officer, merely suffering demotion.

The damage inflicted by My Lai on the image of the US and its armed forces as ‘crusaders for freedom’ persists to this day. As so often with stories of this kind, the institutionalised cover-up and the surge of public support for those who carried out the offences, make even uglier reading than the narrative of the original massacre. The apologists for C Company, and indeed for the US army, tried to make a case that, while it may not have been entirely acceptable to murder Vietnamese peasants, it was understandable and excusable.

Jones’s cool, comprehensive account, which rightly devotes most attention to the responses to the massacre, both within and without the US army, concludes that the GIs in Charlie Company were ‘not much different from the young men who have fought in every war’. He applauds the courage, decency and steadfast refusal to acquiesce in barbarism, despite ferocious institutional pressure, exhibited by the handful of soldiers who reported the crimes, most notably Hugh Thompson, who to the end of his days was plagued with abuse as a ‘commie’ and ‘traitor’, receiving hate mail and death threats from people who called themselves ‘patriots’, today doubtless Trump supporters.

Calley steadfastly maintained that he had just followed orders at My Lai; that he did his duty as he had been trained and briefed to interpret it. Some of his former soldiers took the same line. Varnado Simpson, however, became ever more haunted and morose, especially after his own ten-year-old son was killed in a shooting accident: ‘When I looked at him, his face looked like the same face of a child that I had killed and I said: “This is the punishment for me killing the people that I killed.”’ He killed himself in 1997, aged 48.

After Vietnam, and before US forces fought in Iraq and Afghanistan, their soldiers and Marines were educated about the need to uphold moral and legal standards in ‘wars among the people’. During recent conflicts in which Western forces have been engaged, there have been atrocities – yet even the Abu Ghraib scandal cannot be compared with My Lai.

If anything, it is the folks back home – in Britain as well as the United States – who need retraining about the importance of civilised values on the battlefield. Again and again, when British soldiers are charged with offences towards prisoners and civilians, some newspapers and members of the public rally in support of the accused, not the victims. Consider the recent case of a Royal Marine sergeant convicted of killing a wounded prisoner, recorded on his helmet camera. His sentence was commuted following an outcry. It was almost certainly wrong to convict him of murder, rather than of manslaughter, but I remain troubled by the reflection that, if his defence of extreme stress had been offered by a Taliban fighter who had killed a wounded British prisoner, it seems questionable whether it would have been found acceptable.

Jones has performed a useful historical service by compiling as thorough an account as we are ever likely to have of this defining act of military barbarism. If his concluding passages fail to provide a wholly satisfactory closure, that is probably because no closure is attainable. We hate to be brought face to face with the fact that Western soldiers, poorly led and operating in a climate of endemic racial contempt, are capable of acting as appallingly as the Germans who murdered Jews and other captives in the Second World War.

As the US Marine sergeant said to Phil Caputo in 1965, young men of all nationalities are capable of doing unspeakably cruel, barbaric things, if their commanders allow them – even by default – to suppose that these are acceptable. Possession of automatic firearms empowers killers of all kinds in peace and war – think of Las Vegas – to do terrible things with remarkably little effort or impulsion, and often correspondingly little hesitation. My own researches leave no doubt that while My Lai was quantitatively the worst war crime committed against civilians by US forces, many killings similar in character, if not in scale, took place elsewhere.

Underpinning the tragedy of that war was the fact that while US forces professed to be fighting for the freedom of the Vietnamese people, successive Washington administrations were impelled almost exclusively by the perceived domestic and foreign policy interests of the United States. Since successive presidents cared so little for the Vietnamese, why should their soldiers be expected to do so? Marine David Evans wrote home on arrival in Vietnam in December 1967: ‘Dear Mom and Dad, this place is really a filthy country … I wouldn’t trust the people as far as I could throw them.’ Here was the mood that created the My Lai massacre. It seems less surprising that it afflicted so many private soldiers than that it also infected a substantial proportion of their senior officers. We need to keep reading about My Lai for the same reason we must continue to struggle to understand the men who carried out the Holocaust: only by acknowledging how low men can sink in wars is there any hope of training and conditioning them to rise higher.