Earlier this month, the Islamic State of Iraq and Syria (ISIS) began an offensive on the strategic Syrian border city of Kobani – a Kurdish stronghold – besieging it from the east, west and south. A victory in Kobani would move ISIS closer towards fully consolidating its gains northern Syria, strategic due to its oil resources and location near the Turkish border.

Since then more than 140,000 refugees, mostly Kurds, have fled to Turkey from Kobani and its surrounding villages. Aid organizations have called it the largest and fastest exodus of civilians since the conflict began.

As ISIS edges closer, local Kurds have called upon the U.S. to expand its airstrikes from Raqqa, Deir Ezzor and Hassakeh to the areas around Kobani.

“ISIS is trying to take over areas that have oil and ones that bring a financial source of income,” says Dilshad Othman, a Syrian Kurdish and IT specialist living in Washington, D.C.

“The whole Kurdish area has lots of oil and good infrastructure, and not a lot of damage has been done to that infrastructure. It’s a very strategic point for ISIS.”

Here, Wladimir Van Wilgenburg, who studies the Kurds at the Jamestown Foundation, argues that Turkey needs to join the U.S.-led anti-ISIS coalition in order to stop its advancement into Kurdish Syria, and the significance of the potential fall of Kobani.

Syria Deeply: How far entrenched is ISIS in Kurdish parts of northern Syria? How was ISIS able to make these advances?

Wladimir Van Wilgenburg: This is not the first time they are attacking this area, but this is the first time they have taken so many villages from the Kurds. They have captured dozens of Kurdish villages and the YPG have evacuated around 100 villages, but I don’t think they will take the city from the YPG. One of the reasons why messages from Kurdish politicians sound so alarming is because they want to have U.S. support for airstrikes.

ISIS is fighting from the town of Kobani, which is completely surrounded on three sides, with U.S. artillery, weapons and tanks taken from the Iraqi arms and weapons from the Syrian government, from when they captured an air base in Raqqa, and Russian weapons they captured from the Syrian army. They are using all of these weapons against the Kurds in those areas.

Syria Deeply: Which groups are resisting the advance of ISIS into these areas?

Van Wilgenburg: It’s the same groups that have always been fighting in Syria: The People’s Protection Units (YPG) that are affiliated to the Kurdistan Workers Party and the Democratic Union Party, so basically the PKK. The last ISIS video “Flames of War” shows Kobani as a target, and they mentioned the YPG and PKK as secularists that should be defeated, but I am not sure why they are doing this campaign at the moment. It’s possible that they see the Kurds as a possible threat in the future, because their areas border ISIS strongholds.

The Kurds could benefit if there are U.S. airstrikes and ISIS weakens, so maybe ISIS wants to give a definitive blow against Kurds in Kobani, so it’s not a threat anymore, especially because it’s close to Raqqa.

Syria Deeply: Are there more ISIS fighters in Kobani now, as a result of them fleeing U.S. strikes in Raqqa and other parts of Syria?

Van Wilgenburg: What the Kurds are saying is that U.S. airstrikes don’t have an effect because most of ISIS went underground. ISIS knew the strikes were coming, so they are using the current situation to attack the Kurds. Most of the attacks are in cities, not in the countryside where ISIS resides and is currently attacking Kurds from. Some people say there have been airstrikes near Kobani now, but they aren’t enough to stop the slow advance of ISIS.

Syria Deeply: What would it take to stop the advance of ISIS in the Kurdish areas of Syria?

Van Wilgenburg: The problem is that Kobani is completely surrounded. The Kurdish areas in Syria are not like the Kurdish areas in Iraq, which are all connected. There are three enclaves in Syria. Afrin is now safe, the enclave in Aleppo province, because ISIS has been kicked out of Azaz, which is now controlled by anti-ISIS groups. Kobani is now completely surrounded by three sides, and then you have the provinces of Hassakeh and Jazira, but they are bordering Turkey and Iraqi Kurdistan, so Kobani is the easiest target for ISIS because it is surrounded on three sides. That’s why it is dangerous for the Kurds. It will be a big problem for the PKK and the Democratic Union Party; it will be one of the biggest defeats of this war. We saw the same when Kurds lost areas in Iraqi Kurdistan when ISIS attacked.

Syria Deeply: What do you think we’ll see in the coming weeks? What’s the tipping point?

Van Wilgenburg: It really depends on what they do about the U.S. airstrikes, and whether other countries will get involved and coordinate attacks around Kobani. It also heavily depends on Turkey, which is not happy with Kurdish autonomous areas being created on its borders. They are talking about creating a buffer zone, and have a huge problem with the influx of refugees. It depends on if they change their policies towards Kurds in Syria, and if they actively start to participate in the coalition against ISIS. Turkey is incredibly important because it is one of the main countries bordering ISIS territories. Obama needs Turkey if he really wants to eliminate ISIS from Northern Syria. There needs to be development of other non-rebel groups not affiliated with ISIS. Most of the jihadists entered Syria from the Turkish border, so it will be important for the future. Now that all of the Turkish hostages from Mosul have been freed, there are fewer excuses for Turkey not to do anything against ISIS.