ZEHRA CACAN sits on the edge of a fresh grave strewn with flowers and prays quietly. In it lies her 30-year-old son, whose nom de guerre, Serxwebun, means insurrection in Kurdish. He died in January in a clash with the Turkish army on the Iraqi border. Hundreds of his fellow fighters from the Kurdistan Workers’ Party (PKK) are also buried in the Yenisehir cemetery in Diyarbakir. Their graves are distinguished by the red, yellow and green ribbons adorning their headstones.

A few years ago it would have been unimaginable that rebels’ graves could be marked or that a grieving mother could speak in Kurdish. “We cannot believe how free Kurds are here. Back in Syria we were afraid to speak Kurdish even with our relatives,” says Yarin Abi, a newly arrived Syrian Kurdish refugee.

The outlines of the pact are contained in letters from Mr Ocalan relayed by the pro-Kurdish Peace and Democracy Party (BDP) to rebel commanders in Kurdish-controlled northern Iraq and in Europe. The deal is ambitious but simple. The PKK will abandon its 29-year-old fight for self-rule. Mr Ocalan himself says he now favours a unitary state. In exchange the parliament, dominated by Mr Erdogan’s Justice and Development (AK) Party, will pass reforms enabling the Kurds to pursue political goals without risking imprisonment and freeing thousands of activists jailed on the flimsiest of charges.

As part of this, the current constitution, drawn up by the generals following a coup in 1980, will be replaced by a “fully democratic” one that addresses the Kurds’ demands. An article saying that all Turkish citizens “are Turks” will be scrapped, as will another proscribing education in the Kurdish language. Regional autonomy will also be boosted. Under the existing centralised system “my hands are completely tied,” complains the BDP’s Osman Baydemir, Diyarbakir’s mayor. Facing 24 separate court cases on terror-related charges, he complains that he was not even permitted to name a local park after a (Turkish) human-rights activist “because the governor [appointed in Ankara] said no.”

The conflict in Syria, where a PKK-linked Kurdish group is gaining ground, is threatening to spill over the border. Peace with the Kurds is essential if Turkey is to fulfil its dreams of regional leadership. “The prime minister’s political career is at stake, he is utterly sincere,” says Galip Ensarioglu, an AK deputy from Diyarbakir. Not all are convinced. Some think a deal with the Kurds is a tactic to help Mr Erdogan secure his ambition to become Turkey’s first elected president when Abdullah Gul steps down next year. He wants to enhance the powers of the job à la française, which his critics say could make him a dictator. With the main opposition parties firmly against, he has taken to courting the BDP, whose support would win him parliamentary approval for a new constitution to be put to a referendum.

Président Erdogan

The minutes of a recent meeting between Mr Ocalan and the BDP confirmed that the presidency is on the table. To ensure that would-be saboteurs (including Iran and Syria) do not use hundreds of PKK militants based inside Turkey, Mr Erdogan is insisting that they withdraw to northern Iraq. In the coming days Mr Ocalan is expected to call on his men to silence their guns. The chances are that they will; in a gesture of goodwill they freed eight Turkish captives this week. If the army in turn halts its attacks, which are still continuing as part of Mr Erdogan’s carrot-and-stick policy, peace may at last ensue.

The tricky bit is getting ordinary Turks and Kurds on board. Recent opinion polls suggest that most support the talks, and a majority back AK as well. But where would they draw the line? Far more than his Islamist rants against alcohol and abortion, it is Mr Erdogan’s unabashed authoritarianism that worries many Turks. Turkey has become the world’s leading jailer of journalists, many of them Kurds, for example. Yet Mr Erdogan’s supporters counter that the progress Turkey has made in the past decade, including defanging the army and starting talks on joining the European Union, is down to Mr Erdogan’s courage and uninterrupted AK rule. Only a presidential system can avert the paralysis that Turkey endured before AK came along.

As one Kurdish politician says, a stronger presidency is not too high a price to pay for a new constitution that is a stepping stone to greater devolution. The Kurds’ real problem is lack of trust, arising from decades of repression and betrayal at the hands of what they see as an unchanged Turkish state. Such distrust is on show at the Yenisehir cemetery, where Yildiz Capraz, a contractor, performs the Islamic ritual bathing of corpses. Kurdish families do not consider officials “to be respectful”. Her charges have included PKK fighters whose bodies were so horribly mutilated “we could not show them to their families,” she whispers. Meanwhile Mrs Cacan airs the common refrain that “guns won us our rights.” Can they be forgone without ironclad guarantees?

Mr Erdogan’s record suggests he has the skill and the courage to heal Turkey’s biggest wound. His bold embrace of the Iraqi Kurds was among his most successful foreign-policy moves. If Mr Erdogan were now to settle for a presidency with its present powers, not of a French-style monarch, it would go a long way towards easing suspicions about his motives—and clear the way for a constitution embraced not just by Kurds but by Turks of all political and ethnic stripes.