The bombings this week against tourist targets in Antalya, Marmaris and Istanbul have drawn international attention to a struggle that has grown progressively worse and risks returning to an all out insurgent war.

“There has been an escalation in violence, if you look at the intensity of attacks in 2006 compared with 2004/5,” said Fadi Hakura, an expert on Turkish affairs at the Royal Institute of International Relations. “It may get worse unless the problem is not addressed.”

Back in the 1980s and 1990s, some 40,000 people were killed in the conflict between Turkish security forces and the Kurdish Workers’ Party (PKK), which sought the creation of an independent Kurdish state in southeastern Turkey. The war came to an end in 1999 with the capture of Abdullah Ocalan, the PKK leader, who was sentenced to life imprisonment. He called for a ceasefire and an end to violence and the hostilities more or less ceased until 2004. The Turkish authorities, under pressure to meet human rights criteria set by the European Union for possible Turkish membership, responded by allowing ethnic Kurds greater cultural freedoms, like the use of their language. But in the absence of any lasting political settlement, hardliners seized the initiative.

The Kurdistan Freedom Falcons (TAK), which claimed responsibility for the current bombing campaign, are an off-shoot of the PKK and aim to force the authorities to negotiate by damaging the country’s tourist industry, a pillar of the economy. Their relationship to the PKK is not clea but, as The Times reported last week from northern Iraq, it is clear that the PKK has reconstituted itself along the Turkish border where it controls a large swathe of mountainous area and has thousands of fighters based in military camps.

Murat Karayilan, the new PKK leader, said that he wanted a ceasefire and a peace agreement with Istanbul, but his movement is also ready to fight and will be difficult to dislodge from its stronghold.

On the Turkish side, attitudes are hardening. General Yasar Buyukanit, the hawkish new chief of staff, vowed during his inauguration ceremony that defeating Kurdish “terrorism” was one of his main priorities.

Much of what happens next could depend on America. Although heavily over-extended in the region, it has appointed General Joseph Ralston, Nato’s former supreme allied commander, to coordinate efforts against the PKK. His main task will be to stop the group using northern Iraq as a launch pad for attacks against Turkey.

Washington is already struggling to keep security in Iraq. The one area that has so far been relatively peaceful is the northern Kurdish region. Unless it can act decisively to halt the PKK it could find that here too violence breaks out. The Turks have warned that unless Kurdish separatist violence stops it will take action against PKK targets in Iraq.