Only 13 years ago the Turkish and Syrian governments came close to war, a culmination of long-existing tensions over borders, terrorism, water, contending alliances, and domestic factors. From an account of mine about the mood in October 1998:
On Friday, [Oct. 2,] the Turkish chief of staff Huseyin Kivrikoğlu said relations with Damascus had already become an "undeclared war." President Suleyman Demirel announced that "we are losing our patience and we retain the right to retaliate against Syria." He also put the Syrians on warning: "Those who expect benefits from terrorism have to know that they will also suffer from terrorism in the future." Prime Minister Mesut Yılmaz accused Syria of being "the headquarters of terrorism in the Middle East" and reportedly warned Damascus that the Turkish army is on stand-by, "awaiting orders" to attack. A "crisis committee" has apparently been put together at the Turkish prime minister’s office to deal with this issue.
Newspapers bristle with talk of military plans. A leading daily announced that the army’s plans begin with air strikes on Syrian military airports as well as radar and missile installations; a land-based incursion could be considered later on. Another newspaper predicted that Turkish planes could reach the terrorist camps in Lebanon in a half-hour.
I quoted a former U.S. ambassador to Damascus to the effect that "the only thing that would delay the Turks in an invasion of Syria would be the need to stop and drink tea."
But the crisis was averted, then Hafez al-Assad died in 2000 and the AK Party (Adalet ve Kalkınma Partisi) came to power in 2002. For nine years, relations improved between the two states. In October 2009, for example, Turkish and Syrian forces carried out joint military maneuvers near Ankara and a "Turkey-Syria High Level Strategic Cooperation Council" came into being, then promptly announced the signing of almost 40 agreements to be rapidly implemented. Even the border problem concerning the Turkish province of Hatay was shelved, if not solved.