In August 2015, the Islamic State (ISIS) beheaded Khaled al-Asaad, an eighty-year-old archaeologist and official custodian of the ancient city of Palmyra, Syria. His mutilated body was hung above the museum where he had worked for more than forty years. Tied to his body were plaques that said he had been a “director of idolatry” who attended “infidel conferences.” Before he was executed in the town square, Asaad had refused to reveal information about Palmyra’s treasures to his ISIS captors.

Palmyra has been a meeting point between the East and the West for more than two thousand years. With elements of both Hellenistic architecture and Islamic tradition, it is a convergence of cultures and a memorial to world history.

Eckart Frahm, professor of Assyriology at Yale University explained to The Politic, “It makes sense that this is something ISIS does not like if you compare this crossroads of civilizations to the monochromatic views of ISIS, which is extremely simplistic ideology.”

ISIS seized Palmyra in May 2015 and used its ancient theater, a UNESCO World Heritage site, as a dramatic stage for the execution of pro-Assad militants, government soldiers, and anyone else deemed takfir, or impure. ISIS later reduced the temples to dust, looting what could be carried and destroying that which was too large to move.

While Palmyra and its ancient relics may seem like an unlikely target, the city holds strategic value for ISIS. It sits in the middle of important gas fields. Several highways link Palmyra to major cities in Syria and Iraq. The old city’s occupation also carries symbolic consequences.

As Frahm explained, “[Palmyra’s] destruction is focused on the remote past.”

“The situation with ancient sites is more extreme because no one worships any of the gods of Palmyra today, and yet these sites are destroyed as well,” he continued.

Attacks on ancient sites are part of ISIS’ propaganda strategy. Amr al-Azm, an associate professor of history and anthropology at Shawnee State University, has led efforts in Syria to protect artifacts in ISIS territory.

Azm explained that ISIS’ strategy is meant to shock the world. He said, “These atrocities can be prisoners, Westerners dressed up in jumpsuits and paraded around, all filmed.”

These acts are designed to “demonstrate the ability of ISIS to act with impunity and the impotence of the international community to respond,” Azm said.

Destroying a UNESCO World Heritage site, Frahm added, is “an easy opportunity for ISIS to humiliate and provoke the West.”

These atrocities also affect local communities. ISIS publicizes its own narrative of success through these acts, which deters locals from resisting and prompts new members to join.

Peter Stone, the UNESCO Chair in Cultural Property Protection and professor of Heritage Studies at Newcastle University, explained that the videos attract disenfranchised youth. They see ISIS “standing up to rest of the world, standing up to the free market and the political establishment,” he said. “Most of the destruction videos that ISIS produces are spoken in Arabic, so there is an overt targeting of those dissatisfied youth.”

ISIS hopes its destruction of historical sites will detach the people of Iraq and Syria from the past. Evan Ryan, Assistant Secretary of State for Educational and Cultural A airs explained to The Politic, “Psychologically, ISIS is trying to separate Syrians and Iraqis from their history and heritage because then they will be more easily able to absorb them into their own e orts.”

When ISIS brings monuments to the ground, its message is that the caliphate is more powerful than even the greatest civilizations.

According to Michael Danti, assistant professor of archaeology at Boston University, “This is the antithesis of cultural heritage.”

In attempting to destroy the remnants of ancient cultures, ISIS shows that it recognizes that these civilizations, and their legacies, are key to constructing national and cultural identities. Saddam Hussein attempted to forge a connection between Iraq and ancient Mesopotamia. A popular Iraqi cigarette brand was “Sumer,” for the ancient civilization of the same name.

“It was very hard to produce some kind of identity among these people because their nations were essentially artificially created after World War I by diplomats who didn’t really care about the ethnic divides that existed,” Frahm said.

By attacking ancient civilizations, ISIS aims to remove this common identity and replace it with its own extreme ideology.

ISIS also targets ancient sites like Palmyra for its cultural objects, which it considers “un-Islamic” and shirk, or the sin of practicing idolatry. Azm explained that ISIS views Islam as a dulled diamond.

He elaborated, “They see themselves as a movement whose job it is to take this diamond, clean it up, get rid of all these impurities, and its true essence will shine through.”

To carry out their planned purification of Islam, ISIS attacks Shiite shrines and Christian churches. In 2014, ISIS blew up the Tomb of Jonah in Iraq, a site associated with the prophet of the Abrahamic tradition.

“What ISIS is aiming at is a purified radical Sunni version of Islam; any kind of veneration of someone other than Allah is anathema, even if it is someone who, like Jonah, is mentioned in the Quran,” said Frahm.

Stone added, “Members of ISIS believe they have a God-given responsibility to destroy all un-Islamic idolatry.”

The profits from selling cultural antiquities are an important source of funding for ISIS. Michael Danti calls the strategy a “dual exploitive doctrine.” Objects too large to move are destroyed and exploited for propaganda. Those objects that can be transported are looted and sold. Though impossible to estimate how much money ISIS has made selling artifacts, the flow of money is an important and steady source of external funding.

The operations are highly organized. Danti said, “Actions are high impact, and they represent a very planned-out assault designed to enact cultural cleansing, to manipulate cultural identity, and to essentially erase cultural memory as part of establishing the caliphate.”

Other terrorist groups have inspired ISIS. In 2001, the Taliban destroyed the Buddhas of Bamiyan in Afghanistan. They forced prisoners to plant dynamite in every crevice of the giant Buddhas for three days. The Buddhas that had stood 150 feet tall for 1,700 years fell to the ground in an instant. The Taliban claimed the statues were idols, a violation of sharia law. Mullah Mohammed Omar, then the spiritual leader of the Taliban, had said, “How could we justify, at the time of the Last Judgment, having left these impurities on Afghan soil?”

Though ISIS claims to act in the name of religion, it is “not the driving force, but rather the justification for the atrocity,” Azm argued. “You find some verse from the Quran that supports the atrocity you have committed, rather than the other way around.”

ISIS’s targeted attacks have exacerbated the damage to cultural heritage that already happens in war.

Danti explained, “You have all the destruction from combat, all the neglect, all the things that are associated with conflict, which we expect. But on top of that, you have this other destruction.”

These factors, Danti believes, make the destruction in Syria and Iraq the worst cultural heritage disaster since World War II.150825-palmyra-01_6ffd0d35199a9e064e33eab8a019bc43.nbcnews-fp-1200-800

Just as the Monuments Men protected art from the Nazis eighty years ago, a new generation of scholars is combatting the destruction. Archaeologists and historians in Syria and Iraq have worked to remove objectsat risk. And where it is impossible to save cultural objects, much of the work being done focuses on documenting what is being destroyed. The American Schools of Oriental Research (ASOR) documents cultural artifacts, a process that includes everything from working in Iraq and Syria to taking satellite images to conducting online research.

Danti explained this work includes “performing emergency conservation work on damaged mosques and churches, or sandbagging things like mosaics that cannot be evacuated from museums.”

International norms and practices protect cultural heritage under both international humanitarian law and the 1954 Hague Convention.

“If anybody allows cultural property to be destroyed, they are breaking international humanitarian law,” said Stone. Although this is not a deterrent to non-state actors like ISIS, the legal consequences make documentation of cultural destruction essential for future trials.

Governments around the world can play a role in protecting cultural objects. Ryan believes the United States should help to protect cultural heritage around the world. He said, “We are trying to send a message to other countries and cultures that we respect your heritage, we respect your history, we respect your culture.”

The State Department’s anti-trafficking strategy relies on collaboration with other law enforcement agencies. To help recover cultural objects, the U.S. government publishes emergency “red lists,” which detail objects at risk that might be tra cked from Iraq and Syria. The lists are sent to law enforcement officials, museums, and art collectors. The State Department also alerts countries like Turkey and Jordan to watch for objects passing through their borders.

Despite increased enforcement, cultural objects still nd their way to customers around the world. A 2015 report by the Foundation for Defense of Democracies found that the most common customers are art collectors and history buffs in the U.S. and Europe, calling it ironic that they come from “the Western societies which the Islamic State has pledged to destroy.”

Yet, as Danti said, “There are not very many people out there saying ‘I want to buy something from the Islamic State.’” Cultural objects leave ISIS territory through smuggling networks that transport them throughout the world. ASOR hopes to raise public awareness so that people do not unwittingly fund ISIS with their purchases.

“We’re trying to make sure that the liquidation of Syria and Iraq’s cultural legacy is not contributing to the destruction,” Danti said. “It’s a horrible feedback loop.”

As the war persists, scholars know successes will be limited.

“To stop the destruction of cultural heritage in Syria and Iraq,” Azm said, “you need to stop the war. Barrel bombs are going to continue dropping on museums, tunnels are [still] going to be dug, and ISIS from time to time will commit an atrocity.”

Khaled al-Asaad’s nephew remembered his uncle’s despair when ISIS seized Palmyra.

He told The Telegraph, “We knew they would not leave him alone. We used to stand together and watch the trenches and the barricades go up…he couldn’t stop his tears. He’d say they were punishing everything—even the stone.”

Until the conflict ends, brave people like Asaad will ensure that, despite the wishes of those who shatter ancient stone into dust, Syria’s cultural memory will remain.