On the eve of Monday’s referendum on the future of Iraqi Kurdistan, Iranian armed forces conducted a significant military drill on the border between Iran and Iraq as Tehran warned the Kurds not to move forward with the plebiscite. Meanwhile, Iran’s Supreme National Security Council—the entity in charge of crafting and communicating the country’s security strategy—announced that it would halt all flights to and from the Kurdistan region’s major airports, Sulaymaniyah and Erbil. According to Tehran, the council took that step after Baghdad requested it to do so. All this activity is hardly surprising; in a region plagued by conflict and terrorism, the Kurdish referendum may just be Iran’s greatest challenge yet. And now that the Kurds have voted for independence despite regional and international opposition, they’ll be starting what will likely become a long, multilayered negotiating process to achieve secession. 

Iran has a longstanding relationship with Iraqi Kurds, and it’s the only country in the region with a substantial Kurdish population to have consistently preserved decent relations with them. Iranian support for the Kurds has received more attention since 2014, when Iran backed certain Kurdish efforts against the Islamic State (ISIS), but the ties go back decades. 

Even before the 1979 Islamic Revolution, the Shah provided support to the Kurds in Iraq. In those years, Iran, joined by Israel and the United States, supported a Kurdish insurgency against the al-Bakr government in Iraq. At the time, Tehran’s backing of the Kurds served two main purposes. First, the Shah shared the United States’ fears about the spread of communism in the Middle East, and the Soviet Union backed the government in Baghdad. Second, the Shah wanted to check Iraq, whose claims over parts of the river bordering the two countries—the Shatt al-Arab, as it’s known to the Arabs, and Arvand Rud, as it’s known to Iranians—had caused longstanding tensions between the two capitals.

The dispute ultimately led to the Iran-Iraq War on September 22, 1980. During that war, the Kurds sided with Iran, and the Saddam Hussein regime targeted both with chemical weapons. Decades later, Iran and the Kurds would again find themselves on the same side of a fight: this one against ISIS, in which the Kurdish Peshmerga fought side by side with the Islamic Revolutionary Guard Corps’ elite Quds Force and Iranian-backed Iraqi Shia militias.

Kurds in Erbil march in support of the independence referendum, September 2017.
Azad Lashkari / Reuters

But if shared threats and interests have brought Iran and Iraqi Kurds together for decades, Iran’s own Kurdish population has made the relationship more complicated. Iran’s Kurdish population of approximately seven million is concentrated in the country’s northwestern and western regions—and that population includes a substantial number of Sunnis. The areas inhabited by the Kurds remain among the most underdeveloped parts of the country; the government has consistently failed to invest there and private investment hasn’t come either. It’s not surprising, then, that even as the Peshmerga are fighting ISIS in Iraq, some Iranian Kurds have joined the terrorist group. And this isn’t lost on ISIS, which has targeted Iran’s Kurdish population for recruitment. The ISIS operatives who conducted the June 2017 twin attacks in Tehran were Iranian Kurds.

Despite all this, much like the many other ethnic, religious, and linguistic minorities that have long threaded the remains of the Persian Empire, Iranians view the Kurds as a natural part of their country’s composition. But the Kurdish referendum complicates things. Rather than seeing it as a single, contained event, Tehran views it as opening the door to a more comprehensive effort at cleaving the Kurdish territories off Iran, Syria, and Turkey to create a new country in the region. And that idea isn’t farfetched. Pundits and politicians in the region and abroad have long contemplated doing just that as the solution to what they see as the essence of Middle East insecurity: the region’s borders—mostly drawn by colonial powers. Some have even argued that the days of the boundaries drawn by the Sykes-Picot agreement are numbered anyway. As the journalist Jeffrey Goldberg put it in his support for Kurdish independence in 2014, “no glue could possibly hold that place together.” For Iran, a country that has seen its historic territory chipped at for centuries, Kurdistan isn’t just a concerning prospect—it’s an existential threat.

For Iran, a country that has seen its historic territory chipped at for centuries, Kurdistan isn’t just a concerning prospect—it’s an existential threat.

And it is a threat that Iran has seen before. In 1946, Iranian and Iraqi Kurds founded a short-lived independent state known as the Republic of Mahabad. The Republic of Mahabad was established in Iran and included Iraqi Kurds, notably the most prominent Kurdish leader in contemporary history, Mustafa Barzani. The republic was backed by the Soviet Union, but it collapsed in less than a year. And Barzani and the Shah would continue to have a tumultuous relationship, one of partnership against a backdrop of suspicion. Partnership and suspicion last to this day. In the run-up to the Kurdish referendum, the head of Iran’s Quds Force, Qasem Soleimani, met with Masoud Barzani, Mustafa Barzani’s son, president of the Kurdish Region, and architect of the referendum, even as Iranian forces were increasing pressure on the Kurds.

If Iraq’s Kurds succeed in creating and sustaining a functioning state, Iran will certainly be deeply affected. First, a successful independence movement in Iraq would almost certainly revitalize similar Kurdish efforts in Iran. And that, in turn, could lead other minorities to push for independence. Second, the Kurdish region shared by Iran and Iraq has long been an easy zone to cross—a feature appreciated by smugglers and dissidents alike. In fact, at the peak of the international sanctions against Iran, the city of Mahabad was a hub for businesses bringing goods from Iraqi Kurdistan to Iran’s Kurdish area before sending them off to other parts of the country. The ease of movement, shared language, and common media outlets between the Iraqi and Iranian Kurdish populations will make political spillover likely. Third, the Kurds are known in the United States as forces for moderation. After all, they have typically sided with the United States against tyrants and terrorists, including Saddam and ISIS. But they, too, have more dubious groups within their ranks. Iran’s Kurdish areas are home to a number of Salafist groups, including some with ties to al Qaeda and the Muslim Brotherhood. And ISIS recruitment efforts in the region have added fuel to the fire. The referendum could serve to empower these groups, which is why it has, according to the United States, already hurt counter-ISIS efforts. 

A statue pays tribute to the Kurdish peshmerga in Kirkuk, September 2017.
Ako Rasheed / Reuters

The referendum could also have implications for Iran’s relations with the rest of the region. In fact, it may be the first development in a long time to bring key players together. Barzani and other Kurdish leaders maintain that the plebiscite’s goal isn’t to start redrawing borders now. Instead, it’s aiming to kick off negotiations between the Kurds and Baghdad. But for Iran (and other countries in the region), the referendum would get the ball rolling, and it’d be difficult to stop it before it crashes through other established borders. As a result, Iran and Turkey have already vowed to take measures to stymie the Iraqi Kurdish efforts for independence.

In that, they’ll be cooperating with Iraq, one of Iran’s key strategic partners in the region. In fact, the referendum is likely to strengthen the ties between Iran and Iraq. For its part, Saudi Arabia is on opposite sides with Iran in most theaters in the region, from Afghanistan to Syria to Yemen. But the Saudis joined the chorus of regional leaders calling on the Kurds to postpone the plebiscite. The United States, too, stated that it might curtail its support and aid to the Kurds if they move forward with independence. And today, the United States continues to maintain its official position that Iraq’s territorial integrity and national unity are its top priorities. This leaves out one key regional player—Israel. Prime Minister Benjamin Netanyahu, whose chief foreign policy preoccupation has been containing Iran, is perhaps the only important leader in the region to have supported the creation of a Kurdish state, which he sees as a potential bulwark against Iranian expansion and aggression. 

The referendum generated a substantial turnout. But far from a definitive answer to the Kurdish question, the plebiscite is just the start of a long process. And that process will unfold as key players in the region are gearing up to halt Kurdish independence. Already, Turkish President Recep Tayyip Erdogan has stated that his country’s armed forces are ready at the border. For its part, Iran has flexed its muscles in a significant drill by the border and deployed the Guards and conventional military as well as a whole host of weapon systems, including missiles and drones. It has also attempted some back-channel diplomacy. Indeed, Iran may be facing its greatest regional challenge yet since the Iran-Iraq War, a development that Iran believes will only serve to exacerbate an already dire security landscape in the region. 

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  • ARIANE M. TABATABAI is Director of Curriculum and a Visiting Assistant Professor at Georgetown University’s Edmund A. Walsh School of Foreign Service in the Security Studies Program and an International Security Program Fellow at the Harvard Kennedy School’s Belfer Center.
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