Even before launching its intervention in northwest Syria on August 24 it was clear that Turkey would do its utmost to forcibly prevent Syria’s Kurds from dominating the entirety of Syria’s northern border.

Since June 2015 the Kurds have controlled the entirety of that northeastern border when they connected their two main cantons of Jazira and Kobani – territory which stretches from the Syrian border with Iraq all the way to the eastern bank of the Euphrates River. Turkey intervened in the remaining 100-kilometer-wide swath of territory stretching from the west bank of that river to the sole remaining isolated western Kurdish canton of Afrin – which was controlled by Islamic State (ISIS) militants and other armed groups.

Turkey’s intervention has two clear goals, forcing ISIS militants from the border and preventing the Kurds from joining Kobani with Afrin. Further south from the border sit the cities of Manbij and al-Bab. Manbij was captured by the Syrian Kurdish People’s Protection Units (YPG)-led Syrian Democratic Forces (SDF) in mid-August, after an offensive and siege that lasted almost three months, with close US air support and Turkish acquiescence – that was given in return for a US promise that the YPG contingent in the SDF would quickly withdraw back to the east bank of the Euphrates, which they have not.

Al-Bab is 50km west of Manbij. Turkey does not want the YPG to take al-Bab (and has began threatening to remove it from Manbij also), fearing that it will enable them to use it as a launchpad to reach Afrin and finally create a corridor which will make all of their territories in Syria contiguous.

On October 19 Turkey began heavily bombing YPG positions, boastfully claiming to have killed between 160 and 200 of their fighters. The YPG claimed at least 15 were killed in that incident. Syria furiously threatened to shoot-down Turkish jets over its airspace if such an incident occurred again. Turkish jets consequently stopped flying airstrikes in Syrian air space when Syria reportedly activated air defense missiles covering that border region.

In addition to this Damascus has R-77 air-to-air missiles, the Russian-made equivalent to the American AIM-120 AMRAAM, for its MiG-29s, which could also pose a grave danger to Turkish F-16s. Therefore, any offensive launched by Turkish-backed Free Syrian Army (FSA) rebels against al-Bab can only count on Turkish artillery support – Turkey’s 155mm self-propelled F-155 Fırtına (Storm) howitzers have a range of 40km, al-Bab is about 30km from the Turkish border.

Washington warned both sides several times to avoid clashing and focus their attention and efforts on fighting ISIS. But Ankara is absolutely adamant that the YPG be stopped and is clearly prepared to continue bombing the group if it tries to advance against ISIS-occupied al-Bab.

However, here’s the thing: Damascus and its Kremlin backer do not want the Turkish-backed FSA militiamen, doing the bulk of the ground fighting for Ankara in Syria, to advance on al-Bab. This is simply because they know those rebels earnestly want to take up arms against the Syrian regime and see combating ISIS and containing the YPG in that corner of Syria as a mere sideshow to the most important battle in that country, the battle for Aleppo.

Reuters recently interviewed several of these rebels who said as much. If given the choice they’d readily spill their blood to fight the regime. And the last thing Damascus and Moscow want is more opposition forces pouring into Aleppo. This could explain why Damascus reacted with such hostility to Turkey’s October 19 bombing of the YPG. Also, on October 25 a Syrian regime helicopter attacked Turkey’s FSA proxy southeast of the town of Dabiq killing two of the militiamen. None of this has reportedly deterred Turkey from pushing ahead.

Ankara is not willing to acquiesce to an SDF/YPG capture of al-Bab from ISIS, and Damascus doesn’t want a bunch of FSA fighters itching to fight in Aleppo takeover a city about 45km to its northeast.

On the other hand Damascus would certainly view Turkey’s greatest nightmare in that region, an SDF/YPG takeover of al-Bab, as a far lesser evil to a Turkish-FSA victory there. Damascus and the YPG haven’t gone to war against each other – for their own immediate tactical priorities and prudence more so than anything else. Also, while they have violently clashed against each other in the recent past none of those clashes escalated into a full-fledged war. Consequently YPG forces in the Kurdish district of Aleppo are viewed by a lot of Syrian opposition groups as little more than proxies of the regime since they have never joined their armed insurgency against it.

What will happen in the long-term is far from clear. What is clear at present is that ISIS militants entrenched in al-Bab will benefit the most from this impasse until some compromise, or a third plan to rout those militants out which is acceptable to all sides, is put forward.