It was tempting to romanticize. Journalists and politicians, drawn to the region by the promises of the Social Contract, were treated to guided tours and organized conferences. The word “utopia” was often applied in headlines, and comparisons were made between the Y.P.G. fighting ISIS and those who fought the fascists in the Spanish Civil War. Mr. Ocalan’s writings incorporate the teachings of the American philosopher Murray Bookchin and made reference to the Irish political scientist Benedict Anderson’s critiques of nationalism, which gave the Kurdish project worldwide appeal. Defending Kobani, a border town with little strategic significance but huge symbolic importance, raised the profile of the Syrian Kurdish forces in 2014. When the Y.P.G. helped open a safe passage for Yazidis escaping ISIS genocide in Iraq, they were regarded as heroes, not terrorists.

Kurds outside of Syria, particularly in Turkey, hung their dreams of Kurdish autonomy on the dream of Rojava. In 2015, a Kurdish architect in Turkey laid out long-term plans for Kobani. Houses would be built with solar panels, low and whitewashed like on a Greek island, he told me. A Kurdish lawyer drinking tea by the border said he would have never predicted Mr. Ocalan’s ideas would play out in Syria, rather than Turkey. But he was happy about it. “It’s a dream come true,” he said at the time.

Kurdish autonomy and United States support made Rojava a threat to Turkey and to President Recep Tayyip Erdogan. Using the language of counterterrorism, his administration in 2015 began increasing efforts to imprison supporters of the Kurdish movement in Turkey, removing democratically elected Kurdish leaders from their positions and cracking down on protests so brutally as to transform cities in southeastern Turkey into war zones. Last year, Turkish-backed forces took over Afrin, part of Rojava. “Erdogan started a war,” Adem Uzun, head of foreign relations for the Kurdish National Congress, told me. “He was afraid that Kurds in Rojava would achieve something and gain recognition.”

Mr. Erdogan’s attacks in Syria show signs of awakening a political fervor that he had effectively quashed; in Diyarbakir, historically the political center of Kurdish Turkey, small protests have materialized in the streets. “When you talk to people they say: ‘O.K., we have lost a lot here. They destroyed our cities. But at least in Rojava we have made some gains,’” Ramazan Tunc, a businessman and politician who until the 2015 crackdowns was working to open a Kurdish-language university in Turkey, told me. The attacks in northern Syrian, he said, “may trigger unrest.”

To be worthy of protection, Rojava doesn’t need to be romanticized or viewed solely through the lens of American goals in the region. It is a uniquely Kurdish experiment, grown out of decades of military and political struggle in every part of a would-be Kurdistan and constantly adapting to the circumstances of war.

It is rightly criticized. In my reporting, I’ve talked to Kurds who fled the political dominance of the P.Y.D., and human rights groups who have accused the Y.P.G. of recruiting child soldiers. Rumors of a political alliance, perhaps tacit, with the regime of Bashar al-Assad have now been given more weight as a result of a new military alliance in the face of the Turkish assault. Those who consider the revolution delegitimized by any ties to the Assad regime will have their argument strengthened; others will say Kurds, as they often have, are simply trying to survive in an impossible situation.

But Rojava has been successful against astonishing odds, laying the foundations of a flawed but ambitious local democracy. “I do not claim it was a perfect place,” Yasin Duman, an academic whose research focuses on the administration in northern Syria, wrote to me in an email. “But they have taken a huge step toward achieving an autonomous region that is able to accommodate many of the needs of different ethnic, religious and political groups. All this happened when the region was under attack from different groups and regimes.”