Imagine if people had poured onto the streets of New York and London to mourn the death of Adolf Hitler.

A similar insanity has gripped our cities in the aftermath of the killing of Ayatollah Ali Khamenei.

Everywhere one looks there’s sympathy for the devil, as an unholy union of woke leftists and mad Islamists gathers to grieve the passing of a tyrant.

No sooner had Israel bumped off Iran’s woman-hating, gay-murdering supreme leader than lunatics in the West were welling up.

The “pro-Palestine” student group at Columbia University posted “Death to America” on X.

So cut up was Columbia University Apartheid Divest about the strikes against the theocratic tyranny that it borrowed one of the regime’s own slogans.

The same deathly cry was heard in London, as mobs of Islamists and their dumb allies on the left hit the streets.

Some held up placards showing the ayatollah’s face to let everyone know how much they loved that mass murderer.

Across the United States too leftists gathered, in the words of the Guardian, to lament the airstrikes that “killed Khamenei.”

They weren’t only bemoaning US military action, as they always do — they were blubbing over the very missiles that took out a tyrant. 

We’ve witnessed an extraordinary spectacle: Iranians dancing with glee over the death of the brute who oppressed their countrymen, as smug leftists in their stupid keffiyehs entered a state of mourning.

On Whitehall in London I saw Iranian expatriates weep tears of joy as they boogied over the slaying of the ayatollah. 

In Times Square too, Iranian-Americans sang and swayed over the liberation of their country from that bearded hysteric.

Leftists, meanwhile, seem bereft.

Mayor Zohran Mamdani wailed about a “catastrophic escalation” in an “illegal” war.

Sen. Ted Cruz accused the mayor of “rooting for the Ayatollah” — a good description of the hysteria that has swept parts of the West.

An Islamic center in Watford, just a mile from where I live in London, held an event for Khamenei titled “Remembering Our Father.”

Another London Islamic center in London expressed “deep sorrow” over the ayatollah’s demise.

Tears have been shed Down Under, too, as mosques in Sydney and Melbourne offered condolences upon the “martyrdom” of Khamenei.

Aussie Prime Minister Anthony Albanese called these weeping sessions “inappropriate.” Understatement much?

The vilest thing I’ve seen was an Antifa account on X attacking Iranians in New York for celebrating the ayatollah’s death.

It’s an account with nearly 250,000 followers: “Watch the cockroaches dancing and waving US and Israeli flags,” it said.

Imagine calling yourself “anti-fascist” even as you brand other human beings “cockroaches.”

These lowlifes are actually cribbing the language of Iran’s Islamofascists, who likewise look upon ordinary Iranians as “cockroaches” to be crushed.

Perhaps we shouldn’t be surprised by all this Khamenei grief. 

Over the past two years we’ve seen the silver-spoon Israelophobes of the Ivy League sing the praises of Hamas.

We’ve seen “Queers for Palestine” and other suicidal leftists link arms with Palestinian militants who would throw them off the top of a tall building given half a chance.

It follows that these people would mourn the passing of the ayatollah, the great benefactor of those antisemitic, anti-American movements.

The madness of the past few days confirms that anti-war activism has curdled into straight-up anti-Westernism.

What masquerades as anti-imperialism is really just a blind loathing for America.

It’s less the heir to the peace movements of old than a rancid outgrowth of the anti-civilizational trends that run riot on our woke campuses.

That leftists have so creepily cozied up to a regime that views America as the Great Satan makes perverse sense — because that’s how they view America, too. 

Both the mad mullahs and the wacky left see the United States as the source of every earthly ill, a morally corrupt nation born from the sin of slavery that is now messing up the globe.

There’s a curious reverse racism at play: In treating the West as responsible for every bad thing, the left infantilizes the rest of the world.

It treats other nations as the childlike victims of Big Bad America.

This is why Mamdani & Co. say it’s “escalation” when the United States and Israel bomb Iran, but not when Iran gave the go-ahead to Hamas’s fascistic invasion of Israel Oct. 7 — because according to their hyper-paternalistic Third Worldism, the West is the cause of all evil.

Their hypocrisy is staggering.

They said nothing when tens of thousands of Iranians were massacred by the regime just weeks ago.

Yet now they sob into their hankies because the regime’s top dog is dead. 

They really are the useful idiots of radical Islam. 

Brendan O’Neill is chief political writer for the British online magazine spiked.