By direct threat I mean direct attacks on Turkish forces.
I think the main objective of Turkey in Northern Syria is to prevent the creation of a Kurdish state along the Southern border and combating PKK as a first priority in the counter terrorism efforts. If countries like Egypt and UAE were not involved in the guaranteeing for SDF I don't think I would be so concerned. By adding these Arab countries which will buy the local tribes and chiefs and give the opportunity to SDF of which the YPG is our main priority terror target in Syria to exist in the Arab territories the calculations start to become harder.
My personal hope for the destruction of the base of the terrorist organization PYD/YPG was based on taking control of the Kurdish populated areas, invest there and place a decent alternative to what PYD gave them before. Free and support the opposition Kurdish parties to PYD which were destroyed and their members killed or jailed, give security to the people and secure prosperity for the areas due to the border crossings with Turkey from which there would be a traffic of goods.
With the Arab forces coming with their money and promises to the Arab part of the SDF the situation will become very serious and not only we but also the Arab population will be harmed. When the first serious signs of the realization of the operation came there were serious contacts with some Arab tribes leaders and armed militiamen which were ready to cooperate with the Turkish Armed Forces and FSA in the control of the Arab populated areas South but now all the efforts may be ruined because of that possible move because the real objective is not not to leave power bubbles but to be sure that the power will be enough for the PYD/YPG to continue doing what they are doing and we are not talking about the war against DEASH.
They need their voices to be heard in new Syria at first and then they will make it in a such way that their voices will start to be heard in the whole region and that is why Turkey must do what is needed because there are surely preparations going on for the creation of a proxy state which will obey on 100% to their masters and will be big and rich enough to defend the interests of their masters in the region because as we see Turkey is not a country that can be dictated what to do and what not anymore. Compared to the 2003 when Turkey couldn't give even a "musical note" to the US or compared to the times not to long ago when Turkey herself was forced to give another life to the terrorist organization priority one by letting reinforcements cross trough Turkish land now the situation is different. On the night of 15 to 16 July 2016 it was decided with a strong fist what course should Turkey head and that date will stay symbolic for the future of Turkey and the Turkish strategy for years to come.