A convoy of peshmerga troops drives toward the frontline in Khazer, east of Mosul, Iraq, last year. (Bram Janssen/Associated Press)

Daniel Serwer is a professor of conflict management at the Johns Hopkins School of Advanced International Studies and a scholar at the Middle East Institute.

With the Islamic State near defeat in Syria and Iraq, the urgent and sanguinary is crowding out the merely important: the referendum on Iraqi Kurdistan’s independence, now scheduled for Sept. 25. The issue will be independence, or not. There will be no alternatives. The referendum will be held in territory the Kurdistan Regional Government controls, including oil-rich Kirkuk and other “disputed” territories. Expect upwards of 95 percent of eligible Kurdish voters to vote “yes.”

Kurds in Iraq have compelling reasons for wanting independence. Saddam Hussein pursued a policy of violent Arabization, displacing hundreds of thousands until the American-led imposition of a no-fly zone after the Gulf War deprived him of control over Iraqi Kurdistan. In 2005, two years after the U.S. invasion, the new Iraqi constitution gave the Kurdish region a wide measure of autonomy.

But the flow of oil revenues from Baghdad to Kurdistan’s capital in Irbil has been erratic, and Baghdad has contested Irbil’s right to export its own oil. Half of Kurdistan’s 5.2 million citizens today are under 20 years old, which means they have grown up with little knowledge of Arabic and Arabs, few connections to Baghdad, and constant exposure to independence aspirations. Iraq, to a typical Kurd in the north, is a distant and chaotic place to which she owes no allegiance. The Kurdish peshmerga forces are playing a vital role in defeating the Islamic State in Mosul. Why not take advantage of the credit they have earned while it is still fresh?

In fact, there are plenty of reasons to proceed with caution. Iraqi Kurdistan lacks critical circumstances to enable a successful move towards full independence. Its oil revenue at current production and prices is inadequate to finance statehood. Its recent signature of an agreement with Rosneft, a Russian-government controlled firm with U.S.-sanctioned subsidiaries, suggests desperation. While none of Kurdistan’s major political parties will oppose the referendum, they are not agreed on how to proceed once it has been approved. Kurdistan President Masoud Barzani is assuring everyone that approval will not lead to an immediate declaration of independence but rather to a two-year or longer process of negotiation with Baghdad over the terms of the divorce, including the borders of the new state. Anyone who thinks the under 20s in Kurdistan will patiently wait two years, or that agreement on the borders will be easy, is living in Fantasyland.

International circumstances are also unfavorable. Despite much speculation that improved relations between Irbil and Turkey during the past decade would lead to approval of a referendum and even recognition, Ankara is opposed, not least because it is fighting its own Kurdish rebellion. So, too, is Iran, which is even more vigorous in opposing the referendum. The United States has been less categorical, as the attacks on the Islamic State in Mosul and Raqqa rely heavily on Kurdish fighters, but Washington is not prepared to recognize an independent Kurdistan unless Baghdad agrees to the divorce.

Most of Europe will likely follow Washington’s lead, though in some countries the Kurdish expatriate community may tilt the political weight in favor of independence, leaving Europe divided on the issue. China will oppose Kurdistan’s independence, fearing a precedent for Tibet or Xinjiang. Russia might like to support it, as a welcome post facto precedent for separatism in South Ossetia, Abkhazia, Crimea, Transnistria and Donbas, but it will hesitate to ruin its recently improved relations with Baghdad.

What will Baghdad do? Increasingly, Shiite Iraqis are shrugging their shoulders and saying they are prepared to let Kurdistan go, provided that it doesn’t take Kirkuk or other disputed territories. Baghdad has ample oil resources in the south and many Shiite there see Kurdistan as a distant and unruly place. The Sunni Arab population sees things differently: They don’t want to be left in an overwhelmingly Arab Iraq that would be more than 75 percent Shiite once Kurdistan departs, and they lack the energy resources and territorial control that would enable their own secession. Baghdad’s negotiators will have to drive a hard bargain to satisfy the Sunnis, or abandon the cause and leave oil-deprived Sunni Iraq to fend for itself. The Islamic State would no doubt be back in a heartbeat.

Washington can hope the Iraqi Kurds and Arabs will restrain themselves and negotiate a peaceful and mutually agreed outcome. But hope is not a policy. It is also still possible the referendum will be postponed, but if held, it is likely to undermine the fight against the Islamic State, heighten tension between Baghdad and Irbil, and cause fighting over the territories they dispute. It could also encourage independence movements in South Yemen, eastern Libya (Cyrenaica) and Syria as well as validate Russian-supported independence claims in Georgia, Moldova and Ukraine. None of that would be good for the United States, which should be doing what it can to block the referendum and insist on a successful negotiation before it is held, not afterwards.