The First Scene
The subject of Turkish military intervention in Syria is not considered a good thing. Many reports at the end of 2011 mentioned the existence of a Turkish plan to intervene militarily in Syria, but Turkish ideas and solutions about the intervention and other issues such as creating a safe zone in northern Syria always received American opposition as America always proposed its priority of confronting Islamic State forces above any other priorities . 
The difference in opinions and perspectives between Turkey and the United States led to Turkey preventing NATO airplanes using the Turkish air bases for long periods of time. It soon after agreed to NATO airplanes using the bases following some strategic changes on the ground in northern Syria, and perhaps most importantly Daesh’s withdrawal from areas to the advantage of the Kurdish Protection Units.
The dispute between Ankara and Washington facilitated other parties such as Russia to intervene directly in Syria under the pretense of confronting terrorism at the end of September 2015. The Russian intervention complicated issues for Turkey that did not want its relations with Russia to deteriorate. The Turkish fighter jets shooting down the Russian Sukhoi Su-24 jet in northern Syria complicated the Turkish stances greatly as well as the development of the Russian defense system and operations to stop military and logistical support reaching the opposition. 
From another angle, Turkey has political supported the Syrian opposition in Vienna and Geneva, and publically supported them in front of the International Community with the hope of reaching a political formulation for a solution even if it included temporarily accepting Al-Assad. Despite this support, events on the ground and diplomatic moves led by the UN representative Staffan de Mistura and the American stance only pointed to more negative directions and more destruction on the humanitarian, political or military levels in Syria.