„If such an agreement had not been signed, Turkey could still launch this operation within the framework of the right to self-defence,“ Erol added. He stressed that Turkey`s military operations are in line with the Astana agreement of January 2017, in which Turkey, Russia and Iran are guarantors, and that they are also cemented by the Sochi agreement between the three countries. The Russians presented their own plan on Wednesday during President Recep Tayyip Erdogan`s visit. Putin said the Adana agreement reached by Turkey and Syria in 1998 remained in force. The agreement could serve as the basis for Turkey`s efforts to secure its borders and fight terrorism. Syrian President Bashar al-Assad rejected the idea that the agreement had been signed under pressure and said he had approved it because he had decided that the best thing for Syria was „to be friends with the Turkish people“, which he said was not reconciled with Syrian support for Kurdish groups.  The provisions of the agreement open a legal avenue for Turkey to act in Syria, with the full agreement of Russia. Putin`s goal is to encourage Turkey to cooperate with the Syrian regime. After the withdrawal of the United States, he wants Bashar Assad to take control of all areas controlled by the YPG.
At the same time, the Russian leader referred to the Adana agreement to ensure that the security zone focuses on border security. Finally, he sent a message to YPG fighters and encouraged them to maintain dialogue with the regime. Erdogan had previously said the agreement allowed Turkish forces to conduct operations inside Syria near the Turkish border. Both Turkey and the Syrian regime`s regional ally, Russia, agree that the agreement remains relevant and should be implemented. In 2019, the agreement gained new significance thanks to ongoing Turkish operations on Syrian territory.   The agreement was specifically mentioned in the second agreement on the North Syria buffer zone. Under the Adana agreement, Turkey has the right to drive PKK fighters up to 5 km inside the border with Syria – but they cannot stay long. He said that Turkey had put the agreement back on the agenda because the Syrian regime had not respected it and had fought the ramifications of the PKK in its territories, which led to the activation of ARTICLE 51 of the UN, which grants Ankara the right to self-defence in the event of armed attacks. At first, Syria rejected the Turkish demands, but after important negotiations it decided to partially accept the end of the PKK`s presence in Syria. Prior to the agreement, the Syrian government allowed Ocalan to leave the country instead of handing it over to the Turkish authorities, as required by Turkish request. Instead, he was put on a plane to Moscow.
 The Adana agreement between the then Turkish President, S-leyman Demirel, and the late Syrian President Hafez al-Assad was re-discussed in foreign policy circles last week, 21 years after his signing. Syria`s decision to expel Ocalan and negotiate with Turkey was linked to its concern about the strength of the Turkish army in the face of its own weakness. However, a few years later, Syrian President Bashar Assad said in an interview that „the deportation of Ocalan was not out of fear, but because we preferred you. We could either be friends with the Turkish people, or prefer the Kurds and lose you. As our preference was with you, we sent Ocalan. In signing the agreement, Syria recognized the PKK as a terrorist organization and pledged not to provide financial, logistical or military support.