A few thousand Kurdish rebels fighting in a lost cause for a homeland which would take territorial bites out of Iraq, Turkey, Syria and Iran are endangering the fragile stability of the entire Middle East and the cohesion of the Nato military alliance. The actions of the PKK - the Kurdistan Workers' Party - might also put the final nail in the coffin of Turkey's bid for membership of the EU. Ankara has already authorised a mini-invasion of northern Iraq in retaliation for PKK raids against its territory and citizens. Thousands of tanks and troops have been mustered, but have yet to roll across the frontier. A guerrilla ambush which yesterday killed at least 12 Turkish soldiers and reputedly took others hostage may, however, have brought the moment closer when Turkey, the anchor of Nato's southern flank, will launch its military might into a neighbouring country against the wishes of the US and the fledgling Iraqi government, and precipitate a fresh round of bloodshed in an area already awash with blood.

The rebels have occupied bases in the Candil mountains of northern Iraq. A sister group known as Pejak (Kurds who attack Iranian rather than Turkish targets) has sanctuaries in the same remote location. Despite appeals by Ankara to Baghdad and Washington, no internal move has been made to halt the insurgents' depredations. Turkey, for its part, refuses to channel requests for a crackdown via the Iraqi Kurdish regional government which controls the oil-rich sector of northern Iraq. To do so would be seen as tacit acknowledgement that Kurds in Iraq are entitled to the autonomy claimed by the PKK in Turkey. The Iraqi Kurdish authorities, meanwhile, have vowed to resist if Turkish troops encroach on their territory, even though they have no great love for the PKK and consider it a trouble-maker. Just to stir the pot, Syria has announced that it supports any military action taken by Turkey to safeguard its borders and the lives of its soldiers and civilians. Damascus has its own problems with fractious Kurds. Iran has been shelling villages inside Iraq in retaliation for Pejak attacks on its border guards.

The PKK was branded a terrorist organisation by the US, Ankara and the EU after a campaign of bombings and ambushes in southern Turkey between 1984 and 1999 killed more than 37,000 people. Most of those who died were Kurdish civilians caught in the crossfire. The US, stretched to its military limits by Iraq's Sunni and Shia insurgencies, is, meanwhile, desperately trying to persuade Ankara to exercise restraint. The best hope for a stay of action is the fact that Turkey is due to host a prestigious regional conference on Iraq next month. Diplomacy would dictate that this should act as a brake on early military intervention. But the PKK seems intent on provoking a response which might send its fellow Kurds reluctantly but inevitably into battle on the grounds that ethnic blood ties outweigh common sense or even maintenance of the economic stability enjoyed in Kurdish Iraq. The answer might be to offer Ankara assistance with EU membership in return for a Kurdish-brokered ceasefire with the PKK.