Relations between Syria and Turkey have steadily worsened in the 18 months since violence broke out in Syria. But Ankara and Damascus both have their own reasons not to start a war with each other.
Turkish Prime Minister Prime Minister Tayyip Erdogan and Syrian President Bashar Assad once shared a reputation for being the architects of a new Turkish-Syrian partnership. At one point, members of the two leaders' families even vacationed together. But the once close relationship has dramatically worsened over the last year and half as Assad cracked down on the initially peaceful protests against his regime. The Turkish government has publicly expressed its support for opposition forces in Syria.
"They want to show that they are on the right side of history - that means on the side of the rebellion," said Volker Perthes, director of the German Institute for International and Security Affairs. "They want to help the opposition but want to avoid being pulled into a war."
The consequences of a war with Syria would be difficult to calculate. Turkey faces two enemies along its border with Syria: the Syrian Army and the Kurdistan Workers' Party (PKK). The Kurds, often called the largest people without a nation of their own, have settled mainly in Turkey, Iraq, Iran and Syria. For nearly three decades, the PKK has fought for its own state - or at least for autonomy - with attacks and bombings mainly directed at Turkish targets.
In the 1990s, Damascus supported the PKK and gave the group safe haven in Syrian territory partially because of Turkey's good relations with Israel at the time. During the Cold War, Israel and Turkey were regarded as pro-Western while Syria oriented itself toward the Soviet Union.
With the end of the Cold War, differences between Turkey and Syria narrowed. In 2002, the Islamist-orientated Justice and Development Party (AKP) came to power under Erdogan's leadership and worked to expand its influence in the Arab World - both to increase its own geopolitical importance and to provide a larger potential market for exports from the growing Turkish economy. Good relations with neighboring Syria played an important role in Turkey's plans. Turkey also began negotiating a peace deal between Syria and Israel.
My enemy's enemy
The peace talks ended at the outbreak of the Gaza War in 2009. Turkish-Israeli relations drastically worsened and Turkey began to lend greater importance to its relations with Muslim countries, which also brought Ankara and Damascus closer together.
But the political partnership did not last and in recent months has turned blatantly hostile. The Syrian Army reduced its presence in the northeast of the county, where many Kurds have settled. The region has increasingly come under the influence of the Kurdish Democratic Union Party (PYD), which is the Syrian branch of the PKK. The party recently announced it would not fight Turkish troops in the region, but some observers has said the PYD is working with the Assad regime - a move Turkey would like to oppose.
But Ankara is not looking to engage in a war against Syria.
"Turkey would like the Assad regime removed from power by an opposition regime where it would have considerable more influence," Perthes said. "It does not, however, want to be the warring party that institutes the new regime."
Instead, Turkey permits the opposition in Syria to plan and get weapons supplies in the region surrounding the Turkish-Syrian border.
For his part, Assad also has no interest in a war with Turkey. "That would speed up the fall of his regime," Perthes said.