Islamic State, the jihadist organization bent on conquering Iraq and Syria and establishing a caliphate in the Middle East, has sunk to a new despicable low following disclosures that its fighters vandalized priceless archeological treasures in the Iraqi city of Mosul and bulldozed the ancient Assyrian cities of Nimrud and Hatra.

These barbarian desecrations, which are an affront to civilized norms, took place last week amid reports that the Iraqi army and Shiite militias had launched an offensive aimed at retaking the town of Tikrit from Islamic State, which has seized large swaths of territory in Iraq and Syria since 2013.

In Mosul, captured by Islamic State last June, vandals videotaped themselves smashing ancient statues and artifacts and ripping up books. Shortly afterward, Islamic State foot soldiers went on a nihilistic rampage in Nimrud and Hatra, destroying antiquities in one of the most important archeological sites in the Middle East.

Voicing understandable anger and indignation, Iraq’s ambassador the United Nations said, “They’re taking us back to the dark ages, those people. They are thugs.”

Exactly.

Islamic State claims it has a right to demolish idolatrous images, but this rationale holds no water. Its interpretation of Islam is so perverted and distorted that no reasonable Muslim can take these zealots seriously or consider them legitimate representatives of Islam. They are dragging Islam, a great religion, through the mud and sullying it as the world looks on in utter disgust.

The hideous crimes callously perpetrated by Islamic State in Mosul, Nimrud and Hatra are so beyond the pale that normal human beings cannot fully comprehend them.

Islamic State’s cultural cleansing in Iraq can be compared to the wanton destruction by the Taliban of the historic Buddha statues in Afghanistan’s Bamiyan province in 2001. Carved out from the high sandstone cliffs along the path of the fabled Silk Route to China, these monumental monuments were blown up on the orders of the Taliban’s blinkered leader, Mullah Mohammed Omar, during the last months of Taliban rule in Afghanistan.

In addition to destroying artifacts, Islamic State is selling them on the black market to generate income. It’s encouraging that UNESCO, the United Nations Organization for Education, Science and Culture, is working collaboratively with Interpol and auction houses to track them down and bring unscrupulous dealers to justice.

Unfortunately, the looting of Middle Eastern antiquities is nothing new. The practice goes back thousands of years, when grave robbers pillaged and desecrated the tombs of the pharaohs. More recently, looters ransacked the museums of Baghdad following the U.S. invasion of Iraq in 2003.

And lest it be forgotten, the current civil war in Syria has proven to be disastrous for the cause of preserving historical sites. Krak des Chevaliers — a 12th century Crusader castle that awed the famed T.E. Lawrence, known otherwise as Lawrence of Arabia — has been damaged, as has the Old City in Aleppo. Both are UNESCO World Heritage sites, yet they’ve been shamelessly used for military purposes by the Syrian rebels battling the government of President Bashar al-Assad.

Irina Bokova, the director general of UNESCO, has correctly called Islamic State’s vile actions war crimes that should be addressed by the International Criminal Court in The Hague. The protection of cultural heritage is not a luxury, but an imperative, she declared in New York City recently.

Islamic State has committed a litany of crimes, from persecuting and harassing religious minorities to beheading journalists, aid workers and homosexuals. And now it’s stealing and wrecking unique antiquities that belong not only to Iraq but to the world.