Russia suggests that the deal, if fully implemented, could resolve one of the most difficult disagreements in the Syrian conflict – the status of the YPG. Russia said wednesday that Syrian and Turkish forces should figure out how to work together in northern Syria on the basis of the Adana Agreement, a 1998 security pact, the RIA news agency reported. The Syrian government has since said it no longer feels bound by the deal, but that it retains a “willingness” to return if Turkey stops supporting the Turkish-backed Free Syrian Army and other armed rebel groups in Syria and withdraws its troops from Turkish-occupied areas in northern Syria.   Turkey and Syria signed the agreement on October 20. October 1998 in the southern Turkish city of Adana, 11 days after Abdullah Öcalan, the leader of the Kurdistan Workers` Party (PKK), was forced to leave his long-standing refuge in Syria. Under the agreement, Damascus pledged to recognize the PKK as a terrorist group, close PKK camps and ban all PKK activities on its soil, attempt or extradite captured PKK fighters, and prevent PKK leaders from using their territory to travel to other countries. The two sides also agreed to establish a direct telephone link, working groups and joint mechanisms between the security agencies to define measures against the PKK. In 2019, the agreement took on a new meaning due to contemporary Turkish operations on Syrian territory.   The Agreement was explicitly mentioned in the Second Agreement on the Buffer Zone of Northern Syria.
The provisions of the agreement provide Turkey with a legal path to act in Syria with Russia`s full consent. Syria initially rejected Turkey`s demands, but after lengthy negotiations, it decided to partially accept the end of the PKK`s presence in Syria. In the run-up to the deal, the Syrian government forced Öcalan to leave the country instead of extraditing him to Turkish authorities in accordance with Turkish demands.  Instead, he was put on a plane to Moscow.   The Adana agreement lasted until 2011, when open Turkish support for the Syrian opposition in the context of the Syrian civil war ended all goodwill between the two countries and the Syrian government again began to support Kurdish groups as a counterweight to Turkish efforts in Syria.  The Syrian government claims that Turkey violated the agreement made by the agreement by arming rebel groups in Syria.  In 2012, Turkish officials accused the Syrian government of directly supporting the PKK.  Another point of contention is whether the agreement is technically an agreement or a letter of intent. The agreement, signed by the Turkish Foreign Ministry`s Deputy Undersecretary of State, Ugur Ziyal, and Syria`s head of political security affairs, Major General Adnan Badr Al-Hassan, was not ratified by the respective governments or parliaments in order to obtain the formal status of an intergovernmental agreement. Some observers view the document simply as the minutes of a meeting.
The agreement is based on Damascus` recognition of the PKK as a terrorist organization and the prohibition of all activities of the group and its affiliated organizations on its territory. Although the deal is still technically in force, Turkey has called for the ouster of President Bashar al-Assad since the start of the war in Syria in 2011 and has severely frayed diplomatic relations. Similar to the Adana Agreement, the agreement requires Syria to prevent the PKK and its extensions from using its territory for the establishment of camps, training centers and other facilities; prevent them from recruiting militants and acquiring weapons; and preventing the financing of terrorism through smuggling and trafficking. However, it does not allow Turkey to intervene unilaterally. With regard to the Adana Agreement, the Agreement provides for the establishment of joint mechanisms and working groups. Article 7 states that both parties “shall explore the possibilities of joint operations if necessary.” The Adana agreement is the result of the mediation efforts of Egypt and Iran and responds to Turkish demands that Syria stop supporting the PKK, declares the group a “terrorist” organization and expels its leader Abdullah Öcalan from the country. However, another more formal document exists between the two countries: the agreement on joint cooperation against terrorism and terrorist organizations, which was signed in December. 21, 2010, by Turkish Foreign Minister Ahmet Davutoglu and his Syrian counterpart Walid Muallem, to promote the Adana Agreement. The 23-article agreement entered into force on 26 April 2011 after approval by the government and parliament, replacing the Adana agreement.
The agreement had a three-year validity period, which was automatically extended unless one of the two sides withdrew, but with the outbreak of the Syrian conflict, it became irrelevant. In addition, Turkey`s border policy allowed the passage of weapons and militants into Syria, which encouraged the uprising. From Damascus` point of view, it is Turkey that has blatantly violated the agreement over the past eight years. The main objective of the agreement was to restore Syrian-Turkish bilateral relations, although the Turkish delegation insisted that full normalization would not be achieved until Syria responded to even more demands, including stopping what Turkey considered to be “inciting other Arab League member nations against Turkey.” and cooperation in the arrest of Öcalan. These requirements were annexed to the text of the agreement.  The publicly available text of the agreement does not contain any provision allowing Turkey to enter Syria at a depth of five kilometers. Turkish politicians and experts say the law stems from a secret provision that both sides have hidden from the public. The only relevant document that has emerged so far is a letter dated 22 October 1998 sent by Turkish Foreign Minister Ismail Cem to the President of the European Commission providing information on the agreement.
The letter, a copy of which was seen by the journalist, cites an “Annex 4” of the agreement, according to which “the Syrian side understands that its failure to take the necessary measures and the security obligations set out in this agreement gives Turkey the right to take all necessary security measures within a radius of 5 km deep in Syrian territory.” Turkey and Syria signed an agreement in the Turkish city of Adana in 1998 that defused tensions that brought the two countries to the brink of war. Under the Adana agreement, Turkey has the right to drive PKK fighters up to 5 km (3 miles) inside the border with Syria – but they can`t stay long. .