NOTE: on July 25th Turkish fighter jets followed up their strikes against Islamic State (IS) with attacks on camps inside Iraq of the Kurdistan Workers' Party (PKK), the militant group that for decades has waged an intermittent guerrilla campaign for Kurdish autonomy in Turkey. The following day, the PKK responded with a car bomb against a Turkish military convoy in the eastern town of Lice that killed two Turkish soldiers, according to the government. The air strikes and car bomb brought a clear end to a tentative cease-fire between the government and the PKK that had held for two years; the PKK had already violated the cease-fire last week by killing four Turkish policemen. America considers the PKK a terrorist organisation, but supports related groups of Kurdish fighters in Syria. The strikes made it clear that while Turkey may at last have joined the military campaign of the American-led coalition against IS, it will also continue to oppose the growing regional power of the Kurds.

AFTER a year of hesitation, Turkey has come off the fence and joined the American-led coalition’s military operations against the jihadists of Islamic State (IS). On July 24th Turkish F-16s carried out airstrikes for the first time against IS inside Syria. The army said jets hit three targets in areas south of the border province of Kilis, where a Turkish soldier was killed on July 23rd by suspected IS militants firing from the Syrian side. Also on July 23rd, Turkey announced it will let coalition aircraft use the NATO airbase at Incirlik to hit IS targets. Turkey’s long refusal to do so had led to tensions between Turkey and America, and prompted accusations that Turkey’s Islamist government is colluding with the jihadists.



Turkey’s ruling Justice and Development (AK) party has always denied such claims. On Friday Turkish police raided more than 100 properties in Istanbul and detained 252 people thought to be linked to IS. The crackdown was most likely prompted by the July 20th suicide bomb attack in the border town of Suruc that killed at least 32 people. Most of the victims were university students planning to deliver volunteer aid to the nearby Syrian Kurdish town of Kobane, destroyed in an IS attack last year. The bomber was identified as Turkish national who had joined IS six months ago.



Western diplomats say Turkey had already agreed to let America use Incirlik for offensive operations before the blast. General John Allen, Barack Obama's special envoy to the region, has been working on a deal for the best part of a year. But the Turks had resisted, demanding in exchange that America declare a no-fly zone over Syria, help establish a safe haven on the Syrian side of the border and give as much military priority to removing Bashar Assad from power as to combating IS. A safe haven would help prevent further refugees from coming to Turkey, already home to nearly two million Syrians displaced by the conflict.

Turkey also frets about blowback inside its borders, where IS is believed to have established a sizeable network and recruited hundreds of fighters. But Mr Obama fears a safe haven would lead to America having to commit ground forces. Western officials say their priority remains destroying IS, not toppling Mr Assad. So what prompted Turkey’s shift?

Many believe the move was made to salvage ties with America. Mr Obama has publicly rebuked Turkey for not doing enough to stop the flow of foreign fighters and weapons to Syria. But the immediate cause for the reversal appears to be Turkish fears that its reluctance was deepening America’s friendship with the Syrian Kurds. The People’s Defence Units (YPG), a Syrian Kurdish militia, has become America’s top partner against IS inside Syria. This worries Turkey because the YPG is closely linked to the Kurdistan Workers’ Party (PKK), the rebel group that has been fighting on and off for decades to establish Kurdish self-rule in Turkey. The YPG’s steady expansion along the border stokes Turkish fears of a new Kurdish entity that would be become a magnet for millions of Turkish Kurds who support the PKK.

Last month, with the help of American air power, the YPG wrested control of Tel Abyad, a town on Syria’s border with Turkey that had served as a supply line to the IS capital of Raqqa. This allowed the Kurds to link Kobane to the areas they control further east, all the way to the Iraqi border. Turkey fears that their next move will be to punch westwards through IS-controlled territory to link up with Afrin, the third Kurdish-administered canton. America may have given assurances that this will not happen, to help convince Turkey to join the fight.

Turkey's change of mind will have a major impact on the intensity of the air campaign against IS. Incirlik is only a few minutes’ flying time from Syria, compared with the long haul to IS strongholds from bases in Jordan, Iraq, Kuwait and the Gulf. That means the sortie rate can rise: pilot fatigue will be lower, and fewer missions will require aerial refuelling. Its also means that strikes called in by surveillance drones will leave mobile targets much less time to disperse or hide.

However, American claims that the decision is a "game-changer" may prove optimistic. Strategists warn that air strikes may degrade IS, but without competent forces on the ground, they will not destroy it. Some in Washington are sympathetic to President Erdogan's goal of a safe haven, but Mr Obama has shown no sign of budging.



In Turkey, sentiment over the new policy is mixed. "The AK is finally cleaning up the mess it created itself," says Kadri Gurel, a prominent columnist who was sacked this week by Milliyet, a newspaper, for his critical tweets about the government. But on Twitter, Turks with Islamist sympathies complained that their government had "betrayed the Ummah [the Islamic community]", and similar sentiments.

Meanwhile, after a two-year ceasefire, the PKK has resumed its attacks inside Turkey, killing four policemen over the past two days. This will complicate American support for the YPG. The move was “wrong and stupid and is bound to rub off on the YPG,” said a senior western official. The PKK will remain on America’s terror list “for many years to come.”