It was a perfectly benign-looking tree, festooned with colorful bracelets, in an idyllic setting. If you didn’t know its grim secret, you’d think it might appear in a story book as the perfect tree under which to sit for a romantic picnic. But it does have a loathsome and bloody history.

The bracelets honor the infants and toddlers who met their deaths here when men swung them by the heels and smashed their heads against the trunk. The tree is located at Choeung Ek, the best known of some 300 “killing fields” in Cambodia where between 1975 and 1979 the Khmer Rouge forces, under the leadership of the dictator Pol Pot, imprisoned, tortured and murdered millions of men, women and children – yes, even babies – in a genocidal campaign that wiped out as much as a fourth of the country’s population.

There is a quiet serenity that one often finds among such former venues of slaughter, due in part to a deliberate effort to maintain respectful silence, and in part because of a spontaneous reclamation of the spot’s natural tranquility. If not for the markers and tributes, you’d never imagine that such unspeakable horrors occurred here less than half a century ago.

But they did, and there are macabre silent witnesses, in the form of skulls systematically arranged on shelves in a pyramid-shaped monument to the victims – skulls on which you clearly can see the holes left by some of the wide assortment of gardening tools (also on display) used to carry out the mass executions, in order to spare the expense of bullets.

Some five hours to the north, just outside Battambang, is another such site we examined, a “killing cave”. Beside the cave are statues depicting some of the tortures the victims were subjected to – including being boiled in liquid and having their tongues ripped out – before being hauled, already dead or half-alive, to a nearby hole where they were tossed in to fall about 50 feet to the floor of the cavern.

Near this killing cave, wild monkeys cavort and millions of bats fly out of another cave every day promptly at dusk. The former murder facility is surrounded by temples, ruined and still fully functional. The genocidal mania, in other words, took place in an ecologically rich setting, and was sandwiched both geographically and historically between lengthy pursuits of spiritual bliss.

Why were the victims singled out? They were perceived as a threat to the regime (even babies, apparently). Pol Pot wanted to establish a totally agrarian society with a totally uneducated populace, so he closed schools and exterminated teachers – or anyone else who even appeared scholarly. Some citizens were executed simply because they wore glasses.

What could possibly possess human beings to engage in this kind of sub-human conduct, to the point of bashing out the brains of babies against a tree? Quite simply, they were swept up in a frenzy that smothered all their reason, all their heart, all their soul, all their humanity. Nothing mattered to them except their cause.

Some people have made much of the fact that the Khmer Rouge were communists. But that’s hardly an adequate explanation. There’s nothing in communist creeds that calls for such brutality and genocide.

The Nazis were not communists; on the contrary, they despised and persecuted communists. But even though fascism is inherently more amenable to horrific behavior than communism, it would be theoretically possible to live in peaceful coexistence with Nazis – although you probably wouldn’t want to, certainly not on the same block.

In any case, the soldiers at Auschwitz were not simply following orders when they committed atrocities against prisoners; no such orders were given. (They were ordered simply to kill people, though there is not one case of a Nazi soldier being punished for failing to carry out such an order.) They were grotesquely abusive on their own initiative, just as were the Khmer Rouge troops three decades later. And as were certain concentration camp prisoners in Germany who were elevated to positions of authority within the camp and awarded the honorific title of capo. Even they plunged into a whirlwind of enthusiasm that prompted them to abuse their fellow inmates.

Even MAGA cultists, with their sorely limited capacity for comprehension, seem to grasp that getting intoxicated on ideology and power can seriously impair your judgment. Or at least they’re willing to use that as a defense if they get caught, say, breaking into the Capitol and attacking police officers.

“I didn’t mean any harm. I just saw everyone else going inside and breaking glass and smearing feces on the wall and trying to kill people, and dang it, I just got so pumped up on the group mentality thing that the next thing I knew, I found myself doing the same thing.” (Bear in mind that these are the same people who will insist that anyone who is the least bit unruly at a BLM rally should be buried under the jail; and further, that one such individual is solid proof that BLM on the whole is a violent organization.)

Sorry, but it won’t wash. Sure, we all sometimes do rash things that we later regret. But there’s a big difference between flying off the handle and slapping someone who makes jokes about your wife, and trying to overthrow the government because you’ve committed to buying into a lengthy campaign of lies.

People who perform mass atrocities, whether it’s slaughtering people with gardening tools or gunning down students in school or indulging in ritual group suicide with a poisoned fruit drink, are people who have given their radical beliefs complete control over them. Attacking the Capitol is only two or three steps away from bashing the heads of infants against trees. It’s a matter of degree, not kind. Cambodia is still recovering from what happened here decades ago. How long will it take the U.S. to recover if the MAGAts get their way?

This doesn’t mean that ideologies are in themselves necessarily destructive. But you should be conscious of how much your ideology demands that you inflict damage on the rest of the world; and how much of yourself you’re willing to sacrifice in pursuit of that ideology.