A small group of gunmen attacked a military parade of Iran’s Revolutionary Guard Corps (IRGC) on September 22 in the city of Ahvaz in the southwest of Iran. At least 29 people were killed and more than 60 injured in the attack, which happened in the regional capital of the Khuzestan province, where ethnic Arabs form the majority of the population (Arabi 21, September 22). Islamic State (IS) claimed responsibility. The Iranian government, however, insisted that the attack was the work of local Arab nationalist groups with backing from Arab nations and the United States (Al Jazeera, September 22).
The states that the Iranian government has accused of being behind the attack have vehemently denied any involvement. There was an initial claim of responsibility from Ahvaz Arab nationalists, however it was somewhat vague and attributed the attack to Ahvazi resistance—more of a generic expression than one particular group (Al Qabas, September 24). On the other hand, IS’s claim of responsibility came with a video of three of the alleged attackers. The video was published by IS media arm Amaaq news agency (Al Arabiya, September 23).
IS Eyeing Iran
By targeting Iran, IS is seeking to consolidate its claim of representing the Sunnis of the Middle East and prove its credentials as a Salafi jihadist group. In a landmark 2014 statement about the division between IS and al-Qaeda, previous IS spokesman Abu Muhammad al-Adnani criticized al-Qaeda leader Aymen al-Zawahiri for blocking the jihadists from attacking Iran. Al-Zawahiri, according to the statement, did not want the fight with the United States and its allies to be distracted by fighting the Shia (Al Arabiya, May 14, 2014). IS launched its first major attack in Iran on June 7, 2017, when it targeted the Iranian parliament and the shrine of the founder of the Islamic Republic, Ayatollah Khomeini. (Al Jazeera, June 11, 2017).
Iran and Responsibility
Iran’s insistence on ignoring IS’s claim of responsibility for the Ahvaz attack could be understood in the context of the regime’s handling of the public protests and Iran’s confrontation with the United States and its allies. Since U.S. President Donald Trump announced the withdrawal from the Iran nuclear deal and re-imposed sanctions on Iran, the pressure has significantly increased on the Iranian regime. Although the United States maintains that it does not have a regime change policy in Iran, Tehran is worried about the potential consequences of people’s resentment toward the regime and the economic difficulties the country is experiencing. In recent months, there have been several public protest in various cities across Iran (Sky News Arabia, July 1).
As much as the Iranian regime is willing to direct its people’s anger after the Ahvaz attack toward the United States and other national enemies, it also seems to be willing to play down any indication of IS involvement. One of the main themes of the public protests in recent months was protesters’ opposition to Iran’s involvement in Syria and Iraq and other parts of the Middle East (Youm 7, June 24). Protesters linked the economic hardship inside Iran to its military involvement outside Iran. The regime claims that confronting IS outside Iran aims to stop it from launching operations inside Iran, and accepting IS’s claim of responsibility for the Ahvaz attack could cause more public anger (Al Dostor, April 23, 2016).
On the other hand, promoting the theory of Ahvaz separatists involvement with alleged backing from the United States, Sunni Arab countries, Israel and even remnants of Saddam Hussein’s Iraqi regime seems to be a more convenient cause to rally the support of the Iranian people (Arab48, September 22).
Khuzestan is Iran’s richest province—80 percent of Iran’s oil exports come from the province and most of its oil and natural gas reserves are under Khuzestan’s soil. The province and its predominantly Arab population, however, suffer neglect, lack of development and heavy handed security measures (Sky News Arabia, April 3).
The Ahvazi nationalists attribute all that to discrimination against Arabs from a Farsi dominated government. Ahvazi Arab nationalist movements have been calling for national rights for the Arab people of Khuzestan for decades. Those who resorted to violence have launched several attacks on the regime’s military and economic assets. The most prominent of the Ahvazi groups operate in exile and call for independence of the province, which they believe was annexed illegally by Iran in 1925.
The Harakat al-Nidhal al-Arabi (Arab Struggle Movement for the Liberation of Ahvaz, or HNA) is one of those groups. It was founded in 1999 and since 2005 has claimed to have a military presence on the ground in Khuzestan. It was the spokesman of the group who claimed that Ahvazi nationalists launched the attack, but he provided no further evidence. In fact, the group later distanced itself from any involvement in the attack apparently after IS’s claim of responsibility (Ahwazona, September 23).
IS is well known for not working with nationalist groups of any type. It is unlikely that IS would coordinate with other groups in Iran. Iranian authorities run the country tightly, making such operations hard to coordinate. Both IS and nationalist groups never claimed that they coordinated with each other in the recent attack in Ahvaz or elsewhere. IS, however, has shown significant ability to exploit the public resentment of marginalized communities against exclusionary governments. This pattern was clear in the Sunni areas in Iraq and it led to major IS expansion and military advances in 2014. 
No clear signs of the swift Iranian response that Iran’s Foreign Minister Javad Zarif vowed have emerged. Iran’s response, however, might not come in a clear or immediate shape. Putting the attack in the context of Iran’s confrontation with the United States and with regional foes is a very convenient position for Tehran. Doing so, however, also adds to the tension in the broader Middle East, between Iran and its allies on the one side and its regional opponents on the other.
By launching the attack, IS demonstrated for the second time that despite its retreat from most of its strongholds in Iraq and Syria, it is able to hit Iran, the major Shia powerhouse in the Middle East. Operations against Iran, which have proven difficult, will always be important for IS in order to consolidate its status as the most powerful jihadist group even as its Caliphate is in tatters with military defeats in Iraq and Syria. (Arabi21, September 26).
Iran maintains that it is fair to its Arab and other ethnic and sectarian minorities. Therefore, it is unlikely to embrace reform in provinces like Kurdistan, Sistan-Balushistan or Khuzestan. These areas contain widespread public discontent and the most economically vulnerable suffering due to the U.S. sanctions. They will likely experience more violence from the regime and the separatist groups.
 Shia Islam in Iran is in the position of the Church of The State since the Savaid Dynasty rule in the 16th century. That status was enhanced further after the Islamic Revolution in 1979. Although most of the Ahvazi Arabs are Shia they claim that they are discriminated against because of their ethnicity. Interestingly there has been a growing movement of converting to Sunni Islam among Ahvazi in order to distinct themselves completely from the Iranian rulers and their faith. Active insurgencies also exist in the ethnic Baluchi majority Sistan-Baluchistan province south east of Iran and the Kurdish majority Kurdistan province in the north west, populations in both provinces are Sunni Mulsim. There has not been major IS infiltration in those regions yet.