CNN Global Public Square
The Kurdistan Workers Party (PKK) will dominate the news in the coming days. The PKK, a group known for its violent attacks against Turkey, is fast becoming part of the new trilateral power game between Turkey, Iran and Syria as Bashar al Assad cracks down on demonstrators in his country.
In the 1990s, Iran, whose authoritarian regime disliked secular Turkey next door, asked Syria to harbor the PKK so it could attack Ankara to hurt Turkey's standing as the political antidote to Iran.
Then, Turkey, Iran and Syria all became friends with the rise of the Justice and Development Party (AKP) in Turkey. The PKK issue disappeared, or so it appeared.
Turkey and Syria started a dialogue after Ankara forced the Assad regime to stop harboring the PKK. Turkey massed troops on its border with Syria in 1998. Turkey did not fire a single bullet, but the very credible threat of use of force convinced Assad to change his behavior.
Then with the start of the Iraq War in 2003, Turkey and Iran became, in a sense, friends. Alarmed by the U.S. military presence to its east in Afghanistan and to its west in Iraq, Tehran concluded that it needed to win its neighbor Turkey to break the grip of the U.S.-led ring of isolation forming around it. Iranian support for the PKK ended, as if cut with a knife, the day U.S. troops started landing in Iraq.
Eight years later, Tehran is re-evaluating its strategic environment. With U.S. troops leaving Iraq and Iran gaining influence there, Tehran feels that it can act differently towards Turkey.
Meanwhile, Turkey emerged as the key opponent of the Syrian regime's brutal crackdown. It has threatened action against Assad if the killing does not stop. In response, Damascus has decided to make things difficult for Turkey. U.S. and Turkish officials suggest that the Syrian regime once again allows PKK activity on its territory.
Since Damascus knows that it would almost certainly face a Turkish invasion if it were to allow PKK attacks from its territory into Turkey, it has turned to its ally Tehran for assistance.
Tehran, already annoyed that Turkey is trying to push it out of Iraq, has been glad to help. Iran desperately needs to end Turkey's policy of confronting Assad. If not countered, this policy will usher in the end of the Assad regime in Syria, costing Iran its precious Levantine client state. Hence, Iran's age-old strategy against Turkey has been resuscitated: using the PKK to attack Ankara from another country in order to pressure Turkey.
Accordingly, since the beginning of the summer, the PKK has attacked Turkey from Iraq, killing almost 100 Turks as well as kidnapping dozens of people.
Thus forms the Middle Eastern "PKK circle": the more people Assad kills, the more hardline Turkey's policies will become against Syria. This will, in turn, drive Iranian-Syrian action against Turkey through PKK attacks from Iraq. PKK attacks will rise.
Turkey, Iran and the Assad regime are locked in a power game over Syria's future. Either Ankara will win and Assad will fall, or Tehran will win and Ankara, hurt by PKK attacks, will throw in the towel and let Syria be.
Soner Cagaptay is director of the Turkish Research Program at The Washington Institute.