Last month, Turkey's readiness for an operation against the PKK terrorist organization in Sinjar caused a diplomatic crisis on the Ankara-Tehran line. The words of Iran's ambassador to Baghdad regarding a possible Turkish operation were not accepted or welcomed by Ankara.

Although mutual tensions appear to have cooled for now, Iran-Turkey relations face problems that could resurface with the new geopolitics on the horizon. In general, while the opinions of experts in Ankara point in this direction, there are no opinions from Iranian officials that prove otherwise.

In fact, as Tehran's current policy portrays, Iran is trying to deny that the PKK, its offshoots and other terrorist groups are the most important security threat not only to Turkey but also to Iraq, Iran and Syria – the entire region. However, there are historical facts and recent statements confirming Iran's rapprochement with the PKK and its extension groups, though these are not today's issue.

Last month, an Iraqi official announced that the PKK and Hashd al-Shaabi (Popular Mobilization Forces – PMF) forces, an umbrella group of mostly Iran-backed militias, have been increasing their presence in Sinjar. Sheikh Shamo, who advises the head of the Kurdistan Regional Government (KRG) about Yazidi affairs, said 15,000 members of the Hashd al-Shaabi militia had been deployed in Sinjar.

According to a report by Daily Sabah's Dilara Aslan dated March 7, another Iran-backed paramilitary group in Iraq, Harakat Hezbollah al-Nujaba, threatened to attack the Turkish military if it continued to carry out counterterrorism operations in northern Iraq two weeks ago. The group, which is designated a terrorist organization by the United States and receives military assistance, training and advice from Iran and part of the Hashd al-Shaabi, warned the Turkish military and the government to revise their plans.

An important panel was held this week by the Center for Iranian Studies (IRAM) where Turkey's possible Sinjar operation, the historical relations between Iran and the PKK and Shingal (Sinjar) Resistance Units (YBŞ) which consist of PKK militants, and the impact of this on Turkey's fight against terrorism in the region and Iraq, were discussed.

The president of IRAM, Hakkı Uygur, said that despite Iran and the PKK representing two different ideological fronts, they could take a common position if their shared target was Turkey. “Especially recently, cooperation between the two has increased at the center of the Sinjar operation discussions,” Uygur stated.

Pointing out that the statements by Iran's ambassador to Baghdad, Iraj Masjedi, targeted Turkey over the Sinjar operation, Uygur noted that Masjedi was a name that came to the fore after Qassem Suleimani, the commander of the Iranian Revolutionary Guard Corps (IGRC) who was killed by the U.S. “The PKK-Iran relationship was a relationship that was no longer hidden after these statements. Turkey did not perceive Masjedi’s statements as diplomatic but rather as an attack on Turkey's presence in Iraq. The latest statements from Iran indicate that a possible Sinjar operation will not be easy. But as long as the PKK and its extensions continue to be a threat to Turkey in the region, Turkey's presence there will continue,” Uygur added.

Providing a historical timeline over Iran-PKK relations, IRAM expert Çağatay Balcı said, “Iran and the PKK's cooperation in the region has increased, especially since 2010.” He added: “They both need each other in the region. At the moment, they both are struggling on the Iraqi line. The weight of the Iranian wing within the organization also increased during this time.” Balcı also noted that Turkey's possible Sinjar operation could be affected by the elections in Iran, which will be held in June, and said that the determination of the Iraqi central administration, as well as Iranian influence in the country, are also important factors in this matter. “The pragmatic relationship between the PKK and Iran has developed over the past 40 years and their common goal is Turkey in the region. They have instrumentalized each other against this goal,” Balcı added.

As Balcı stated, the failure to make sufficient progress in Iraq’s Sinjar agreement, reached in October last year, is also due to the impact of this non-constructive approach by Iran on Iraqi domestic politics.

Contrary to Iran's claims about Sinjar, Turkey has stated at every opportunity that it prioritizes ending the PKK terrorist presence in this region and ensuring the security of Iraq and the Iraqi people.

In fact, Turkey has been working toward ensuring Iraq's unity and welfare, which is a goal that Ankara supports, the Turkish ambassador to Baghdad Fatih Yıldız said last Saturday, underlining that the Sinjar deal seeks to return the region to its real owners.

On Oct. 9, 2020, the Iraqi government announced it had reached a "historic deal" with the Kurdistan Regional Government (KRG), an agreement that will bolster Iraqi federal authority in Sinjar under the constitution in terms of governance and security. The Iraqi prime minister's spokesperson, Ahmed Mulla Talal, said in a Twitter statement that the agreement will end the authority of intruding groups in Sinjar, referring to the PKK. The next day, the Iraqi Parliament said the settlement agreement between the Iraqi government and Iraq's KRG on the status of the Sinjar district will accelerate the return of displaced people.

Following the deal, the Turkish Foreign Ministry said in a statement that it hoped the agreement would be carried out in a way that enables the reinstatement of the Iraqi authorities' control in Sinjar, the eradication of Daesh and the PKK terrorist organization and their extensions from the region, and ensures the safe return of Yazidis and the other people of the region who have been subject to grave oppression and persecution, first at the hands of Daesh and then by the PKK.

The PKK terrorist group managed to establish a foothold in Sinjar in mid-2014 under the pretext of protecting the local Yazidi community from Daesh. Since then, the PKK has reportedly established a new base in Sinjar for its logistical and command and control activities. Around 450,000 Yazidis escaped Sinjar after Daesh took control of the region in mid-2014.

After all these events and comments, Iran's continued tactical and positional cooperation with the PKK and other terrorist groups remains a Sword of Damocles above the Sinjar agreement, which will also lead to continued destabilization throughout the region.

Clearly, Iran's entry into a period of softening with the U.S. under Biden may be the reason why Tehran is insisting on these policies. The U.S. support for the PKK's Syrian arm could also be encouraging in this sense. But eventually, the countries that are and will be side by side in this region are Iraq, Iran and Turkey. Overall, failures to take a common stand against terrorist organizations will one day hit every country.