In 1998, Turkey was gathering its troops at the border with Syria so that the latter’s help to the PKK would cease in the Turkish Kurdistan . This threat led Damascus to expel Oçalan, who was later arrested in Nairobi. Those were the beautiful days of Turkey-Israel-U.S. co-operation. Today, Ankara appears in the headlines as a result of its anti-Americanism and its anti-Israeli feelings. Only one has to see what the best sellers have been so far: the best sold book now is a novel on the war between Turkey and the U.S. followed by Mein Kampf.
Given the circumstances, it is not surprising then that Turkey got closer to Syria and Iran - a rapprochement that started during the Iraq war. Syria is searching for allies; and what is more amazing is the fact that Turkey has responded to this call in a favorable way. In fact, Turkey has always been more inclined to the West than it is to the East and the Arab world. Turkey turns to the Middle East only for the Kurdish problem and the policy of the great powers in the region. The peak of anti-Americanism is connected to the belief that Washington wants to create an independent Kurdistan in Iraq. This has caused Turkey to turn to Syria, which also faces a Kurdish problem. On its side, Damascus feels locked in and does not want to owe everything to Iran, since its strategic interests do not always correspond to each other. Syria expects Turkey to be favorable due to its adhesion to NATO and its links with Washington.
Consequently, such rapprochement owes only to the U.S. policy in the region and could cease very soon if Jalal Talabani showed that the Kurdish want to continue to be Iraqi. Ankara would also depart from Syria if it soon moved closer to the European Union.

Source
Daily Star (Lebanon)

Syria loves Ankara but will the relationship last?”, by Omer Taspinar and Emile el-Hokayem, Daily Star, April 19, 2005.