On Sept. 25, the Kurdistan Region of Iraq (KRI) is expected to hold its long-awaited referendum on independence. While it has generated much nationalist excitement among Kurds in the KRI capital of Irbil and abroad, the central government in Baghdad and the international community have objected to the vote. The United States has mobilized diplomatic capital to persuade Irbil to postpone the vote. Last week, Western diplomats offered an alternative proposal: Postpone the vote and enter into new mediated negotiations with Baghdad. But without ironclad guarantees or a specified timetable, Irbil has rejected those initiatives, continuing to prepare for the referendum.

The referendum was never meant to be a silver bullet, ending negotiations on Kurds’ path to statehood. But recent escalations by all sides have produced a self-fulfilling crisis with the prospect of military conflict, fueled by both Arab and Kurdish nationalism.

Here are five things you need to know:

  1. Kurds are divided 

Within the KRI, support for the referendum is divided along party lines and has exacerbated rifts within them. The primary backers of the referendum are KRI President Masoud Barzani and his Kurdistan Democratic Party, whose support base draws heavily from Irbil and Dahuk provinces.

Although nearly all Kurds support the pursuit of independence, the Sulsymaniyah-based Gorran Movement opposes the timing and procedure of the vote in favor of the Western proposal. The Patriotic Union of Kurdistan, meanwhile, is internally split over the whether to support the referendum.

  1. The stakes have risen

Announced in June 2017, the referendum lacks any legal or binding mechanism to create an independent state. No change in borders or sovereignty will occur the day after. The purpose behind the referendum runs through local, national and international logics. But at the national level, what began as a political tactic by Irbil to gain bargaining power in separation negotiations with Baghdad has evolved into a zero-sum, high-stakes competition over the future of Iraq.

Much of this reaction does not align with the referendum’s intended aim. Pressure from all sides has come down on the Kurdistan as though the vote is a pretext to declare statehood. Iran has warned it may change its security relationship with the KRI, pressure from Turkey is mounting, and the United States has pursued an aggressive diplomatic offensive to postpone the referendum.

Within Iraq, the parliament took steps last week to declare the referendum unconstitutional. It also moved to fire the governor of Kirkuk province — a constitutional power reserved for the provincial council, not parliament. Most recently, Iraq’s judiciary has ordered the referendum be suspended.

These actions have emboldened Kurdish nationalism. This in turn has increased the anxieties of Arab leaders in Baghdad. With the stakes of the vote now perceived to be greater than before, both sides believe they cannot afford to concede. The dynamics are akin to a dangerous game of chicken, with no certainty of which actor, if any, will swerve first.

  1. The United States has not helped

U.S. behavior during this crisis has damaged its relations with Irbil, diminishing its role as a credible broker. The relationship has been in steady decline over the years, and Kurds have been wary of U.S. intentions and priorities for decades. Still, Kurds have relied on Americans to serve as a mediator between Irbil and Baghdad, helping deter violent clashes between both sides in the past. But now American diplomacy has failed to pacify tensions over the referendum. Public and forceful objection to the vote practically abdicated the U.S. role as a balanced arbiter and deflated any incentive for either side to compromise. In public rallies, Barzani did not conceal his frustrations over U.S. behavior and declared that the referendum will go on.

Such public defiance by a Kurdish leader toward U.S. policy is unprecedented. Despite receiving U.S. military support, Kurdish rebuffs to American demands are possible for three reasons. First, the United States cannot credibly threaten to withdraw security assurances while the war against the Islamic State continues or if any regional state powers threaten Iraq’s Kurds. Second, American assistance was never structured to advance Kurdish ambitions, but rather tailored to provide enough support to defeat the Islamic State. Finally, the political risk for Barzani abandoning the vote outweighs the risk of losing support abroad for going through with it.

  1. The referendum undermines Prime Minister Haider al-Abadi

The main impetus for U.S. opposition to begin with was the fear that the referendum would complicate efforts to keep Iraqi Prime Minister Haider al-Abadi as prime minister following the April 2018 elections. However, the push against the referendum may have done more damage to Abadi’s campaign than if Baghdad had maintained its initial approach to simply not support the vote and declare it “illegal.”

No post-Saddam Hussein government has been formed without Kurdish backing. If the Kurds go ahead with the vote despite Abadi’s attempts to stop it, he will look weak. Moreover, the Kurds could use their electoral weight to shop for a deal with other candidates. This raises the stakes for Abadi to keep pressing for a delayed vote, which only further emboldens Kurdish defiance.

  1. The prospect of violence has dramatically increased

Rhetoric has ratcheted up to now involve military threats. No place is more of a potential flash point than the disputed oil-rich city of Kirkuk, which has been under the control of Kurdish forces since 2014. Threats from Baghdad and Tehran have increased risk of a violent clash.

Over the weekend, Abadi warned that Iraq’s military was prepared to intervene in response to any referendum-related violence. Iranian-backed Shiite militias, who have a presence outside Kirkuk, have issued threats of their own against Kurdish forces. Meanwhile, Barzani has pledged to defend Kirkuk. With Kurdish nationalism so high, even small incidents could generate massive responses. All the while, the Islamic State retains a presence in Kirkuk province and could potentially exploit divisions and provoke a confrontation.

This rapid escalation is a striking example of the spiral model, as threats and coercion are being used to gain Kurdish compliance, but end up only emboldening their aspirations. While there is much uncertainty over the outcome, tensions could possibly ease before the vote, with all sides reinterpreting the referendum back within its original expectations.

Morgan Kaplan is a postdoctoral fellow at the Buffett Institute for Global Studies at Northwestern University.

Ramzy Mardini is a nonresident fellow at the Atlantic Council and PhD student at the University of Chicago.