Behind a razor wire fence at the Border Patrol detention center in Clint, Texas, hundreds of children were held in cells. Scabies, shingles and chicken pox, thriving in the insanitary conditions, were spreading. The odor of the unwashed was so virulent that it attached to the clothes of the border agents themselves.

Following the discovery of this and other outrages at the southern border, Rep. Alexandria Ocasio-Cortez talked of “concentration camps”—a false equivalence that inevitably brought wrath upon her.

Did she not understand that Auschwitz was the ultimate concentration camp? It was a gift for the Republicans. It was a short step from that for them to falsely infer that she is an anti-Semite because she so grotesquely under-valued the Holocaust.

Message to all: Be careful with historical analogies. They can backfire.

That also goes for Senator Lindsey Graham, Trump’s most abject lackey. He called AOC and three of her freshmen colleagues “communists”—suggesting a gross level of ignorance and paranoia as toxic as McCarthyism.

Seeking for equivalence is often meaningless when dealing with moral outrages. Each outrage has its own design. The southern border situation reaches the standard of a humanitarian atrocity by any measure of a civilized and decent society.

The over-arching moral challenge is trying to understand how these atrocities are possible in the first place, the kind of people who design them, and the ease with which they can become institutionalized.

Adolf Hitler did not invent the concentration camp. They first appeared in 1896 in Cuba, when the Spanish overlords of the island launched the policy of reconcentración, forcing rural Cubans into camps inside fortified towns. Over 400,000 of them died. A few years later the same idea was adopted by Field Marshal Horatio Herbert Kitchener, one of the worst military commanders in British history, and certainly among the most callous.

Kitchener commanded the British army in the Boer War, in which the British fought for control of southern Africa against the Boers, the Afrikaans-speaking descendants of original Dutch settlers.

When the war broke out in October 1899 Kitchener confidently predicted it would be over by Christmas that year. It did not end until May 1902.

The Boers proved skillful in fighting a larger and more ponderous enemy. They deployed small forces of guerrillas, men who knew the country well enough to harass the British and keep them off-balance.

Tiring of this, in 1901 Kitchener initiated a scorched earth policy, clearing the land of anything that could sustain the guerrillas—horses, cattle, sheep, crops.

Boer women and children and men who had surrendered were rounded up and concentrated in 24 camps, known as laagers. The camps were run by the military and the detainees were housed in tents and fed on reduced military rations. Each camp had one superintendent, one doctor and a few nurses.

“ One would hope that the good sense, if not the mercy, of the English people, will cry out against the further development of this cruel system…. ” — Emily Hobhouse

Throughout the war poor hygiene and sanitation had decimated the British forces—of the 23,000 British troops who died far more succumbed to preventable diseases like typhoid and dysentery than bullets.

The camps, with their minimal resources and over-crowding, were even more lethal. As the term “concentration camp” took hold it began to acquire a horror that cast the British as the instigators of a new kind of war crime. Cartoons were published in France showing women and children withered into little more than skeletons. The French government accused the British of mass murder.

Kitchener was indifferent to the suffering and dismissed concerns from London about the harm being done to Britain’s reputation.

This trait in Kitchener of regarding people as expendable in the cause of military victory had shown itself first in the Sudan where he defeated the Dervish forces led by Muhammad Ahmad, the Mahdi. The British deployed machine guns against sword-wielding tribesmen. In one battle 10,000 Dervish died, against 48 British deaths.

After that victory Kitchener became Baron Kitchener of Khartoum.

One of his officers in the Sudan wrote, “He was always inclined to bully his own entourage, as some men are rude to their wives. He was inclined to let off his spleen to those around him. He was often morose and silent for hours together. He was even morbidly afraid of showing any feeling or enthusiasm, and he preferred to be misunderstood rather than be suspected of human feeling.”

But in southern Africa Kitchener’s methods were under closer scrutiny than in the remote Sudan. The concentration camps were discovered by Emily Hobhouse, a 41-year-old single woman and early human welfare campaigner.

In London she was given permission to visit southern Africa to distribute funds raised to help Boer families. At that point she knew of only one camp but after she arrived she discovered the true scale of the operation. Once the army commanders realized that Hobhouse was taking detailed notes they branded her as a “screamer,” a term used against opponents of the war, and banned others from seeing the camps.

But it was too late. Hobhouse returned to London aflame with outrage at what she had seen. “One would hope,” she said, “that the good sense, if not the mercy, of the English people, will cry out against the further development of this cruel system which falls with crushing effect upon the old, the weak and the children.”

In person Hobhouse, a prematurely matronly figure, was normally reserved and (after a failed love affair) somewhat sad. But her public speeches were passionate and she found herself at the head of what became a moral crusade.

She briefed the leader of the opposition Liberal Party, Sir Henry Campbell-Bannerman. He was appalled and uttered a phrase that became a common cry against Kitchener and his camps: “Methods of barbarism.”

When the Tory government was asked how many people were in the camps they did not know. When they did get the figures they were stunning: more than 43,000.

“ By 1939 there were still far fewer people being held in Nazi concentration camps than had been in Kitchener’s hell holes. ”

Hobhouse knew from what she had seen that a high death rate was inevitable. The conditions in the camps, insanitary and overcrowded, were like a self-sustaining death machine. Families were denied fresh drinking water because “the price was prohibitive.”

Asked how many had died, the official response was “several hundred.” Eventually the official figures were “between 18,000 and 28,000” but no final number was ever established. In addition to the appalling death rate the Boer survivors returned home to find that most of their cattle, sheep and horses had been killed or stolen.

Kitchener, rather than winding up the war when it should have been possible, was bent on sustaining it with increased brutality. Captured guerrillas were deliberately executed in public.

Trying to counter the effect of Hobhouse, the government sent an all-woman special commission to inspect 33 of the camps, all of them hand-picked supporters of the war. This boomeranged: The women confirmed Hobhouse’s story and demanded a number of steps to be taken immediately alleviate the conditions in the camps, including putting medically qualified matrons in charge of every camp, sending out scores of nurses to assist them, and new steps to combat typhoid. Within months of these measures being taken the death rate in the camps had fallen to 2 percent.

At the same time, Kitchener reversed policy and ordered his troops not to round up any more women and children and send them to the camps. It may have seemed that he had suddenly renounced barbarism, but the decision was more cynical than that: by leaving the families with the guerrillas they were encumbered and far less mobile.

The Boers surrendered in 1902 and their territories were incorporated into the Union of South Africa and the British Empire in 1910.

Kitchener’s policies, a combination of inept military campaigns and cruel retaliation, had created the most expensive war since the campaigns against Napoleon in the early 19th century: in today’s money equal to around $350 billion.

The idea of concentration camps on such a scale for non-combatants went into abeyance for a while, totally discredited in Europe until, on March 9, 1933, some disused huts in a gravel pit at Dachau, near Munich, became the first Nazi concentration camp.

The first people sent there were Germans picked out for being critics of the new regime. Jews were among them, but they were there primarily because of their political beliefs, often because they were communists. Gay men were treated more harshly, targeted for “preventive custody” and ruled as a “threat to the people’s community.”

Late in 1937 David Glick, a Pittsburgh lawyer, negotiated with the Gestapo for the release of 120 of the 300 Jews in Dachau, and the British, who ruled Palestine, granted them visas to settle in Palestine. Later Glick arranged for the release of a further 3,000 Jews from other camps and they were sent to Bolivia.

By 1939 there were still far fewer people being held in Nazi concentration camps than had been in Kitchener’s hellholes—in fact fewer than all those who died in his camps, a total of 21,000 in six concentration camps, now purpose-built, at Dachau, Sachsenhausen, Buchenwald, Flossenburg, Mauthausen and Ravensbruck.

The ultimate evolution of the camps into industrialized killing machines was initiated at the secret Wannsee Conference in January, 1942.

Reinhard Heydrich, Hitler’s chosen agent for the Holocaust, outlined his “final solution” aimed at 11 million Jews throughout Europe, reaching as far east as Ukraine and Russia.

Of the roughly half a million Jews who lived in Germany in 1933 only 164,000 remained at the end of 1941. They were destined for extermination at the death camps of the Holocaust, along with millions of others, a level of barbarism that had been previously unimaginable.

It is striking that the “methods of barbarism” exposed by Hobhouse aroused widespread public disgust and outrage in Edwardian Britain. Even at the height of the British imperium this was seen as an intolerable aberration. There was no such reaction in Nazi Germany. The Nazis demanded, and achieved, the assent of silence.

That same assent of silence now envelops the Republican Party, cowed into submission by a racist demagogue. But the silent should understand that they are collaborators and will ultimately have to answer for it. They are as complicit in the barbarism on display at the border as Stephen Miller, the enforcer in the White House behind the so-called “zero tolerance” regime—just as in Kitchener’s regime, a task delegated to people and a system never designed to execute it and deliberately left to face the consequences.