President Trump’s recent Twitter announcement that the United States will pull out of northeast Syria is a shameless and dangerous abandonment of America’s closest ally in fighting ISIS. In the battle against the violent extremists, the mostly Kurdish Syrian Democratic Forces (SDF) have worked hand-in-glove with the United States to destroy the so-called caliphate that once covered tens of thousands of square miles across Syria and Iraq. The SDF did the ground fighting, losing more than 10,000 male and female fighters in bloody street combat against fanatical extremists. Meanwhile, the United States and its coalition allies bombed ISIS positions from the air, coordinated by Special Forces soldiers on the ground.

The coalition was able to defeat ISIS, but its success is now in jeopardy. Turkey has announced that it will attack the SDF-held areas of the northeast—which the Kurds know as Rojava—on the spurious grounds that the Kurdish-dominated forces are “terrorists.” Further, it intends to settle refugees from elsewhere in Syria in these areas, which amounts to the ethnic cleansing of the indigenous Kurdish population. The SDF will now have to turn from combating ISIS sleeper cells to defending itself against Turkey; its commander has already pledged to resist Turkish forces should they attack.

This matters because thousands of ISIS fighters, including many who came from other countries, remain imprisoned by the SDF in Syria. The SDF has pleaded with the detainees’ home countries to take them back, along with tens of thousands of their family members and hangers-on, but they didn’t get very far. A Turkish attack would throw into question what will happen to these violent extremists, who are currently living in refugee camps described by some visitors as a breeding ground for ISIS extremism. Already buckling under the enormous task of holding these fighters, the SDF may not be able to maintain the security of the camps. And while Trump has bizarrely suggested that Turkey should take responsibility for these fighters, Turkey can hardly be trusted, given that it has itself given support to extremist groups.

It’s not just the fight against ISIS that will be imperiled by an American withdrawal. Since the Syrian revolution began, there has been a democratic revolution in northeast Syria. Inspired by the writings of Murray Bookchin, an American political philosopher highly influential in anarchist and municipalist movements, citizens of Rojava have turned top-down government on its head. Local councils at the village level, which include non-Kurds and Kurds alike, make all the decisions. It’s a remarkable and rare model of inclusive self-government.

Moreover, this is a revolution led by women. Women cochair local meetings, administer regions (following the decisions made locally), and lead the female People’s Protection Units, known as the YPJ. Together with male YPG and Arab units, they form the Syrian Democratic Forces. It was a female military commander, Rojda Filat, who led the SDF’s final battle in Raqqa.

Because both groups are led by Kurds and share certain political ideologies, Turkey regards the SDF as associated with the Kurdistan Workers Party (PKK), which has been fighting with the Turkish state for decades. On the basis of this association, Turkey considers the SDF a threat it is committed to destroy and has openly declared its intention to attack Rojava. A Turkish assault will destroy the democratic revolution that has taken place there.

That is not just a tragedy in itself, because it would remove a viable model for the governance of all of Syria. It is for Syrians themselves—all of them—to decide how the country should be governed.

A country deeply fractured by sectarianism and conflict, the confederal model of Rojava—of maximum local autonomy without breaking up the country—is a plausible proposal. Unfortunately, the United Nations has failed to invite representatives of the self-governing areas to participate in its newly formed constitutional committee to discuss the future of government in Syria. This failure is the UN’s for bowing to to Turkish pressure, but the United States and the United Kingdom also bear responsibility. These countries have benefited from the bravery and bloodshed of the Kurds, yet failed repeatedly to stand up for democracy against Turkish hostility.

The West’s betrayal of the Kurds has a long, sad precedent. The Kurds were abandoned when the Ottoman Empire was carved up among the new colonialists, sanctified in the 1920 Treaty of Sèvres. The arbitrary drawing of borders in the Middle East by the French and British divided the Kurdish nation into four populations split between what the imperialists decided would be Iraq, Iran, and Syria as well as Turkey. Only in Iraq, where the Kurdish north enjoys a degree of autonomy, are the Kurds not oppressed by the over-centralized governments of the region.

When I visited Rojava in 2015, local officials argued to me that this “ziggurat” model of centralized government, where sectarian elites fight over the country’s resources, has been a failure for the region. Looking at the mess of Syria and Iraq, and indeed the repression of minority rights in Iran, it’s hard to disagree.

Should the rights of the Kurds in Syria be our business? Setting aside the obvious security interest of restraining ISIS, standing up for the Kurdish people is a broader cosmopolitan imperative. The protection of Rojava against Turkish attack requires a minimal number of American troops, who so far have suffered minimal casualties (though coalition air strikes have resulted in civilian deaths throughout the country).

The SDF keenly cooperates with the United States, so the presence of these troops can’t be compared to US deployments in Iraq and Afghanistan. Here is a rare instance in which US troops are living up to their promise: helping democracy in the Middle East. Given the catastrophic alternatives, this is an alliance that should be celebrated—and, for as long as it’s necessary, maintained.