More than 200,000 Syrian Kurdish refugees have moved into Iraqi Kurdistan. They have crossed an international border to be sure, yet it is, in the Kurdish worldview, a passage from one part of their homeland to another. The Kurds disregard these frontiers, imposed on the Fertile Crescent almost a century ago by Anglo-French power.

No Kurd is lamenting the erosion of the borders in this tangled geography. The partition of the successor states of the Ottoman Empire brought the Kurds grief and dispossession. The Persians, Turks and Arabs secured their own states. Indeed, the Arabs were bequeathed several states in the geography of “Turkish Arabia” that runs from the Iraqi border with Iran to the Mediterranean.

Kurdistan was singularly betrayed, its people divided among Turkey, Iran, Iraq and Syria. Kurdish history became a chronicle of thwarted rebellions. According to a deeply felt expression, the Kurds had no friends but the mountains.

Yet a new life is stirring in Kurdistan. Erbil, the capital of Iraqi Kurdistan, once a forgotten fortress town, is a booming city of shopping malls, high-rises and swank hotels. Oil and natural gas have remade the city, as has its political stability, remarkable when set against the mayhem of Iraq.

The Kurds are shrewd. They aren’t about to claim Erbil as the capital of a restored greater Kurdistan, but it has pride of place in their world. It is the home of Massoud Barzani, the president of the Kurdish regional government, and of almost 5 million people, who are officially part of Iraq but in reality belong to an independent nation. The realists among the Kurds know the power and ruthlessness of the nations that have divided and ruled their world, yet they are determined to make the best of this moment when borders and attachments are suddenly in flux.

Western Kurdistan — Rojava in Kurdish — has given rise to this new sense of urgency. The war between the Damascus regime and the principally Sunni rebels presents peril and possibility for the 2 million to 3 million Kurds within Syria.

The Kurds inhabit fragments of Syria by the Turkish and Iraqi borders, in the northeast; their lands contain the bulk of Syria’s oil. Arab nationalism, the creed of the authoritarian Syrian state, was avowedly racist in its treatment of them, denying them the most basic and cherished right: use of their own language. The regime of the Assads, father and son, has been cunning and devastating in the way it pitted the Kurds against one another.

Yet in the civil war that erupted in 2011, the Syrian opposition has troubled the Kurds, too. The leaders of the Sunni Arab rebellion were committed to creation of their own centralized state. Turkey’s sponsorship of the rebels created suspicions as well. The foreign jihadists who made their way to Syria were yet another source of anxiety.

The Kurds had a small volunteer force of their own, but it was no match for Jabhat al-Nusra, or the Nusra Front, whose Islamist warriors had weapons aplenty, money and unchecked zeal. The group was determined to impose its rule in areas the regime had left. In mid-July, clashes broke out in Kurdish towns and have erupted intermittently since. Thousands of Syrian Kurds have made their way to Iraqi Kurdistan, where they receive help, even as the authorities in Erbil don’t want to encourage an exodus from Syria.

Turkey casts a large shadow. The line that separates the Syrian and Turkish Kurds is artificial. As the prominent Turkish columnist Cengiz Candar observes, the Kurds don’t speak of Turkish and Syrian communities. For them the line of separation was a simple railroad track that allowed them to move to and fro, with ease and freedom.

Turkish Prime Minister Recep Tayyip Erdogan faces a dilemma. He is invested in a peace process at home with the Kurdish Workers’ Party, or PKK, and its imprisoned leader, Abdullah Ocalan. And Turkey has a flourishing relationship with Iraqi Kurdistan, whose oil and natural gas it needs desperately.

Yet the permissive attitude of the Turkish state toward the jihadists battling the Syrian Kurds has been a source of trouble for Erdogan. He has gone a long way toward keeping the jihadists at arm’s length.

The dream of greater Kurdistan is just that. History has given the Kurds a second chance in Iraq and Syria, while Turkish democracy gives them a voice in the country’s direction. Matters are stagnant in Iran, where the oppression of the Kurds is of a piece with the tyranny of a theocracy.

The Kurds can’t erase all the hurts of their modern history and those who choose to stay in Syria remain embattled, yet the isolation that had been their lot is now in the past. At the foot of those once sheltering mountains, a new and a safer life has sprung forth.

Fouad Ajami is a senior fellow at Stanford University’s Hoover Institution. He is the author of “The Syrian Rebellion.”