Last month, in a tone which might best be called unlikely insistence, former British Prime Minister Tony Blair reassured the public that “we” — the UK and United States — “have to liberate ourselves from the notion that we caused” the destabilization of Iraq by the ISIS insurgency. Well, actually you did.

Let’s go back to the Versailles peace conference at the end of WWI, when Britain — with the agreement of the other Western powers — carved the mandate of Iraq out of three former Ottoman provinces. These provinces — Sunni Kurdish, Sunni Arab and Shia marsh Arab — were about as unwieldy as any other artificial country the imperial powers of Europe cobbled together around the world and displayed high potential for instability from the beginning.

In the 1930s the United States supported unification of the Arabian peninsula under the House of Saud, whose official religion was an ultra-fundamentalist Sunni sect known as Wahhabism (coincidentally shared by the al Qaeda terrorists who attacked the US on 9/11).

In 1953, the United States gave powerful impetus to Islamic political fundamentalism by overthrowing Iranian prime minister Mohammad Mossadeq, a secular democratic socialist, restoring the Shah to power. This created a state of affairs in which fundamentalist clerics constituted the primary opposition to the Shah’s autocracy, leading eventually to the overthrow of the monarchy and establishment of a theocratic regime.

Meanwhile, the Eisenhower administration quietly backed still another fundamentalist movement, the Islamic Brotherhood in Egypt, as an alternative to Nasser’s secular socialist model of nationalism.

In the 1960s the United States helped engineer the Baathist military coup in Iraq, thus bringing to power the same regime it eventually went to war with twice.

In the late 1970s the US created the conditions which eventually gave rise to al Qaeda, deliberately destabilizing a stable, secular Soviet client regime in Afghanistan by providing aid to fundamentalist insurgents and provoking a Soviet invasion and decade of bloody civil war. Al Qaeda emerged from among the Islamic fundamentalists fighting a guerrilla war against Soviet occupation in the ’80s, an insurgency the United States armed and trained heavily. The Carter administration destabilized Afghanistan; Reagan poured gasoline on the fire, because giving the Russians their own Vietnam was just too delicious an opportunity to pass up.

In 1990 the United States — perhaps eager for a “splendid little war” to demonstrate the continuing need for a large “defense” establishment in the post-Cold War Era — basically instigated Saddam’s invasion of Kuwait. US Ambassador April Glaspie reassured Saddam that the US took little interest in minor affairs like one Arab country invading another. Meanwhile, with US encouragement, Kuwait engaged in practices like slanted oil drilling on the Iraqi border that inevitably goaded Iraq to invade.

But despite the devastation of Iraq by massive US air attacks and an ensuing decade of sanctions, Saddam’s dictatorship remained a secular regime where most people paid little attention to sectarian differences. Marriages between Sunnis and Shia were about as unremarkable as marriages between Baptists and Methodists in this country. The one force in the Middle East that most objected to this secularism and sectarian peace was al Qaeda — America’s baby. And by overthrowing Saddam and creating a power vacuum, the United States did the one thing guaranteed to give al Qaeda an opening in Iraq. After defeating and dissolving the Baathist regime, the Coalition Provisional Authority established a puppet government organized along sectarian lines, with religious sects rather than ideologically oriented parties as the main axis of political division. That kind of divide-and-rule strategy made it a lot easier to auction off the country to Halliburton, see.

And ISIS itself? Well, as resistance to Assad in Syria turned into an all-out civil war, the United States and American proxies like the Saudis (you know, that country whose Wahhabi oil aristocracy included Osama Bin Laden) armed anti-Assad rebels — some of which went on to become ISIS, a Sunni fundamentalist group so extreme even al Qaeda disavowed them.

So yeah, Tony. You, Bush and Obama — and all the other swine who’ve used the world as their chessboard for the past century — did cause this. All this bloodshed is yours. You own it.

Translations for this article:

• Italian, Sì, Mr. Blair, ISIS È Roba Sua.