The armed banks of the Royava, Syrian Kurdistan, are in effect the YPG, the Popular Defense Units. In the chaos of Syria, they represent one of the most reliable presences in terms of operational continuity, especially in virtue of being rooted in the territory. The northeastern side of Syria is the western sector of the great Kurdistan which then extends virtually to Iraq, Iran and north to Turkey for 400.000 kmq (Italy and Portugal combined). 50 millions of souls who are divided into four different states.
The YPG front would theoretically run between the Kurdish city of Al Hasakah in the north and the Euphrates in the south, up to the Arab city of Raqqa, "capital" of the so-called Islamic State. However, it does extend to the whole strip along the Turkish border, reaching the now famous city of Kobane, more Arab than Kurdish in reality.
Logically, the sector affected by the YPG is strategically decisive for measuring the progress of the Isis militias. The control of the Turkish border would guarantee the Caliphate an enormous territorial continuity, with infinite supply lines.
Alongside the Kurds, depending on the time, both deserters of the ESL (Free Syrian Army), the main force opposing the Assad government, and the regular troops of Damascus are fighting. The common enemy Isis unites all, including the American-led coalition planes that often find themselves in the grotesque situation of indirectly helping Assad's troops, as happened in July 2015 during the reconquest of Al Hasakah.
It is therefore logical that the United States has long considered the YPG as the best ally to face the forces of the Caliphate. In addition to the skills and knowledge of the territory, they are those that apparently represent a lower ideological cost. In this regard it should be remembered that the anti-ISIS coalition in Syria also includes airplanes from Saudi Arabia, the Emirates, Bahrain and Jordan, all Arab countries with Sunni leadership, historic enemies of the Shiites of Damascus (and their Iranian allies).
Unconditional aid from the United States to the Kurds of the YPG would therefore be the most natural development of the Syrian crisis, at least on the delicate northern front.
However, the structural problem of YPG is Turkey. 
Ankara cannot afford weaknesses on the Kurdish question and considers armed militants beyond the southeastern border a real threat to its sovereignty, especially in light of the ill-concealed ties between YPG and PKK. By virtue of its weight within the Atlantic Alliance, Turkey ends up directly influencing Western support for the Syrian Kurds, effectively slowing it down.
Indeed, there are episodes that say a lot about Ankara's attitude in the Syrian context, to the point of exposing its actual deployment alongside the Islamist militias. The capture of Turkish soldiers following the jihadists in Kobane and the passage of Isis militiamen within the Turkish territory to facilitate the siege of the city were the most striking cases last June. The same forces deployed to the southeast to initiate phantom operations against the Islamists are actually mobilized against the resurgence of the PKK, particularly active throughout the summer of 2015.
Ankara's ambivalence about ISIS actually goes much further. The Sunni triptych with Saudi Arabia and Qatar is a partnership now proven not only on a theoretical and ideological level, but takes operational forms in various international theaters. In Libya, Turkey finances the Islamist front of Derna, in Yemen it is on the side of the Saudis in an attempt to cool the Shi'ite outbreak of the Houtis. If we think that relations with Israel, a traditional friend of the Turks, are at an all-time low, the die is drawn.
Ankara's new dynamism embarrasses NATO allies and is symptomatic of two factors in some disturbing aspects:
- A significant rotation on confessional positions in Turkey that contradicts the secular occidentalism taken by Ataturk in the 20 years. http://www.difesaonline.it/geopolitica/tempi-venturi/lepanto-ieri-e-oggi-la-turchia-si-muove
- A greater polarization of the Islamic world on two fronts: one sponsored by Shiite Iran; the other by the Sunni monarchies of the Gulf, which despite being part of the anti-ISIS coalition, are said to be the lenders from many quarters.
Obama's America cannot afford to break away from the Sunni front in which Turkey plays an increasingly important role. Beyond traditional alliances, on the more recent geopolitical level Turkey and Saudi Arabia are also fundamental in anti-Russian function: Turkey is the last strategic piece of the Crimean-Caucasus-Syria semicircle, theaters in which the military presence of Moscow is all other than symbolic.
Ryad for his part is necessary to keep oil production high and consequently devalue the ruble. Not a few are those who suspect that the appointment of the Saudi Faisal bin Hassan to the presidency of the Advisory Group of the Human Rights Council to the UN (a joke for all ...), is part of the lubrication system of allies indispensable to the United States.
Not to irritate Saudis and above all Turks, for America today it is a dogma. This is explained, as reported by the Washington Post, that American supplies destined to be parachuted to the YPG along the Raqqa line, have been waiting for weeks only for the White House order.
The aid would be decisive for completing the Kurdish counteroffensive and even the recovery of the city, highly symbolic of the caliphate. Everything is silent and supplies languish, pace of war against ISIS.
Save at least appearances or nurture good relations with Turkey? Which of these two needs of the Pentagon will prevail is rather easy to guess. The Kurds from guerrillas peshmerga frayed from the past have passed to a real organized army that has already made honor for the international community on the Syrian theater. When they ask for the bill, the most concrete prospect is that nobody will answer. As long as Turkey is in NATO, the birth of Kurdistan will have to wait.
