At first glance, it looks like an ordinary video produced by the so-called Islamic State with all the usual trappings. It’s sleek yet macabre. A young boy—in all probability, not even a teenager—speaks to the camera as he stands on a battlefield. Dressed in military uniform and brandishing a knife, he goes on to behead a “spy.”

But what makes the video almost unique is its language. The boy speaks in fluent Persian and is explicitly addressing the inhabitants of Iran, especially its majority Shia population. While Persian propaganda used to be somewhat of a rarity for ISIS, it has recently become more common.

In this case the young protagonist, “Al-Qatada the Persian,” addresses “all those who take part in and cooperate with the war against the Islamic State” and issues an explicit threat: “We will destroy your land and your home, we will disrupt your security and we will shed your blood.”

At one level, this certainly is an act of desperation. Iranian-backed and in some cases Iranian commanded militias have played a key role fighting ISIS in Iraq and supporting the Assad regime in Syria. The ayatollahs and their acolytes no longer even try to be discreet about their military role in the region, as IranWire has reported.

But ISIS has proved flexible, imaginative, and resilient many times, to the chagrin of its enemies, and its current unconventional offensive against Iran should be taken seriously.

ISIS’s propaganda has long been multilingual. From glossy magazines in English and French to videos in Hebrew and songs in Chinese, it has sought to globalize its outreach. But it is only recently that it has seriously turned to Persian, one of the main languages of the Muslim world and the official tongue in three Muslim-majority countries (Afghanistan and Tajikistan in addition to Iran). Apparently it’s trying to increase recruitment in Iran and target Iranian territory.

Less than two months ago, on June 7, a group of Iranian recruits (mostly Sunni Kurds) staged attacks on the Iranian parliament and the shrine of the founder of the Islamic Republic, Ayatollah Khomeini. Twenty-three people died, including the five attackers themselves.

While Iranians and commentators were caught by surprise, ISIS-watchers would have known that the attack came after months of extensive publishing of Persian-language propaganda. In fact, less than 24 hours before the attack, Radio Free Europe had published a report entitled “IS Propaganda Increasingly Targeting Iran And Its Sunnis.”

In the few months leading up to the attack, four issues of ISIS’s magazine, Al-Rumiyah , had been published in Persian for the first time. These seem to have been a direct translation of the previously-published English output. Articles detailed the supposedly religious justification for the killing of unbelievers. One issue’s front cover featured a blood-soaked blade and gave tips on using to kill using a knife.

More significantly, ISIS produced and posted a sophisticated 37-minute video in March, perhaps timed to coincide with the Iranian new year celebrations, that gave a detailed history of Iran and explained why the country, its rulers and its majority Shia inhabitants should be targeted.

The video recounts the time of pre-Islamic Iran “when the Persian Sassanian empire had installed the religion of Magi [a pejorative term for Zoroastrianism] as its official creed… and people worshipped fire.” The ancient Persian empire is depicted with elaborately-staged reenactments that could be straight from a Hollywood production. The video falsely claims that the Sassanian capital was in “the cities of Persia, in what is today Iran” (the Sassanian capital Ctesiphon was, in fact, near what is today Baghdad, the Iraqi capital).

The historical narrative continues, with the championing of Salman the Persian, a companion of the Prophet Muhammad who, the video explains, helped the Muslims win a crucial battle by advising the prophet to build a moat around their trenches— a common Iranian military tactic at the time. Iranians then “remained Muslims for nine centuries,” the video says, until the rise of Shah Ismail in the 16th century and his founding of the Safavid empire, which made Shia the official religion of Iran. In the video, talking heads remind viewers of the “massacres in Tabriz, Shiraz, Yazd and Mazandaran” by the Safavids.

A Portuguese envoy is quoted as having allegedly documented the destruction of Sunni mosques and killing of the Sunni scholars under the Safavids. It is further alleged that the Safavids turned Abo Lo Lo, the Iranian-descended assassin of Omar, the second Islamic caliph, into a “brave national hero.”

Historical reenactments and documentary-style talking heads might not seem like effective propaganda tools, but the video tries to build a powerful narrative aimed at the Sunni minority, which forms up to nine percent of the Iranian population.

The narrative is updated to the present time with attacks on the Islamic Republic, whose founder Ayatollah Khomeini, it says, “came from Paris with an airplane of French crusaders.”

Along with the other “crimes” committed by the republic, the video points to its alleged attempts to disseminate Shiism around the world, its support for militias in the Arab world and its tolerance of Jewish synagogues and Christian churches in Iran.

The video features a film of Iranian Jews worshiping in peace in Tehran and Isfahan as signs of the Islamic Republic’s un-Islamicness. It also attacks Iranian Sunni imams like Mowlana Abdolhamid, the Friday prayer leader in Sunni-majority Zahedan, who has been a popular stalwart of the Iranian Sunnis due to his efforts to better their conditions and fight discrimination while also countering the influence of Takfiri groups like al Qaeda and ISIS, which regard those who do not share their rigid orthodoxy and heretics deserving death.

In addition to using Persian, the video also features a protagonist speaking in Balochi, a language spoken by about two percent of Iranians, most of them living in the southeast. Another speaks in fluent Arabic and is introduced as Al-Ahwazi, meaning he is allegedly from the Arab-populated southwest of Iran that has long harbored separatist and Pan-Arabist factions but has been mostly immune to Sunni radicalism (the majority of Iranian Arabs are Shia). The video also calls on “Kurds and Persians” to join ISIS and fight Iran.

It is perhaps surprising that it took ISIS so long to target Iran seriously. There have been many reports of the group’s recruitment efforts in Iran since its foundation in June 2014. Analysts believe some Iranians have long been among the group’s forces and may have even been killed fighting for ISIS. But the pace of the group’s propaganda and recruitment efforts has accelerated in the last year.

In June 2016, Iranian media reported that 18 people had been arrested after using the popular Telegram app to join ISIS. Two months later, a military leader reported the killing of two ISIS members in the Western province of Kermanshah in clashes with security forces. Then, Intelligence Minister Mahmoud Alavi said his forces had prevented 1,500 Iranians from joining ISIS.

Just days before the deadly June 2017 attack, authorities in the eastern province of Nangarhar in Afghanistan released a video in which a man, introduced as Yasser from the Iranian province of West Azerbaijan, claimed to have joined ISIS “via the app Telegram.” The recent release of the Al-Qatada video might signal an ISIS effort to further target Iran with terrorist attacks just as it stands on the edge of losing its last territorial holdings in Iraq and Syria.

The group will continue to have major difficulties for recruitment in Iran. Many Iranian Sunnis are under the influence of their official imams and religious leaders who, as the example of Mowlana Abdulhamid shows, often work hard to fight against Takfiri influences. The anti-government and regionalist efforts in Kurdistan and Arab-populated Khuzestan have historically been secular and nationalist.

Baluchistan seems to be the only region in Iran where Sunni radicalism has a foothold (and its capital, Zahedan, was the scene of a major terrorist attack in 2010). But even there, local, regionalist groups will be a serious rival for any outside group.

As ISIS furthers its Sunni-aimed propaganda, however, the Iranian authorities and society will need to remain vigilant. Despite existing discrimination toward Sunnis, senior Islamic Republic figures do not publicly malign or attack them. (This is in contrast to the pressure put on Shias in many Sunni-majority countries, especially Saudi Arabia. There, the Grand Mufti openly accuses millions of Saudi Shias of being unbelievers.)

Ayatollah Khamenei, Iran’s supreme leader, issued a fatwa back in 2010 banning any insult against Aisha, a favorite wife of the Prophet Mohammad who, after his death, fought against the forces of Ali, the first Shia Imam. The same fatwa extended the ban to “insults against symbols of our Sunni brothers.”

This is important, as occasional Shia sermons do include rants against Aisha, who Sunnis hold dear as the “Mother of Muslims.” Sectarianism has undoubtedly been used to bolster Shia militias as they fight in the territories of Iraq and Syria, filled with the holiest of shrines for Shias.

YouTube abounds with anti-Sunni rants by charismatic Persian-speaking preachers. Some Shia mosques in Iran organize festivities on the anniversary of the killing of the caliph Omar, sacred to the Sunnis, and celebrate his assassin, who is said to have been of Iranian descent.

But Iranians must understand that any fanning of the flames of sectarianism can have grave consequences that they will come to regret.

This article is adapted from one by Arash Azizi that appeared originally on IranWire.