On 22 October 2019, in Sochi, Russian President Vladimir Putin received his Turkish counterpart Recep Tayyip Erdoğan. Their five-hour meeting centered around bilateral trade relations and Turkey’s "Operation Peace Spring" in Syria.
The S-400 Air Defense System was delivered on schedule and without any snags. The construction of both the Akkuyu Civil Nuclear Power Plant and the Turkish Stream Pipeline is proceeding according to plan.
The two countries signed a Memorandum of Understanding  on the situation in Syria. It is based firstly on the respect of Syria‘s territorial integrity and Turkey’s security needs, and secondly on the Adana Agreement  concluded in 1998 between the governments of Hafez el-Assad and Süleyman Demirel.
The Agreement, whose clauses have long been kept secret, authorized the Turkish army to go after PKK terrorists launching bomb attacks against it from inside Syrian territory. At the time, the PKK artillery had a maximum range of 32 kilometers, hence the 32-kilometer area occupied today by the Turkish army. In addition, the Syrian Arab Republic had authorized the Turkish army to enforce permanent security measures within an area of 5 kilometers. Such provisions helped to put an end to the Syrian-Turkish tensions engendered by the political asylum granted to Abdullah Öcallan and the PKK.
The Russian-Turkish Memorandum confirms the legality of the Turkish "Operation Spring Peace" within a border area of 32 kilometers with the exception of the city of Qamishli. It makes no mention of US demands to shut down the northern land corridor linking Tehran to Beirut. Moreover, it does not set a deadline for the withdrawal of the Turkish army, which is now likely to impose a military occupation, as it has done in Cyprus and Iraq.
The memorandum also says nothing about the war crimes perpetrated by the Syrian Turkmen militia, serving as the Turkish army’s auxiliary forces, nor does it address the accusations made by Amnesty International  and the Times of London  about the Turkish Army’s deployment of white phosphorus.