Damascus Is Killing Syria’s Most Capable Anti-ISIS Kurdish-Led Force

The Middle East is on fire. In probably the most severe conflagration since the rise of the Islamic State amidst Syria’s brutal civil war, innocent and unarmed Iranians are being massacred by a ruthless regime under the darkness of a complete communications and internet blackout. At the same time, the interim Syrian government of President Ahmed al-Sharaa is subjecting the main U.S-allied force against the Islamic State, ISIS, in the country to sieges on cities in the Syrian Kurdish heartland.

Exactly eleven years ago this month, Syrian Kurdish forces finally broke a ferocious, months-long siege by ISIS of the Syrian Kurdish city of Kobani on the border with Turkey. The breaking of that unrelenting siege, as was unmistakable at that time, marked the Stalingrad moment for the self-styled Islamic State caliphate, which inflicted genocide on the Yazidi minority of neighboring Iraq. An ad hoc alliance with the United States, which provided decisive air strikes, began during that heroic battle. The Kurdish forces established the multi-ethnic Syrian Democratic Forces later in 2015 and fought on to liberate every square inch of Syrian territory annexed by the self-styled caliphate. By March 2019, they succeeded in that goal, capturing the sole remaining village of Baghuz on the Iraqi border. Since then, they’ve kept guard over thousands of captured ISIS militants and their families languishing in prisons, makeshift detention centers, and camps.

Today, Kobani is once again under siege, this time by Syria’s new security forces commanded by the interim government of President Ahmed al-Sharaa, which spearheaded the toppling of the long-ruling Assad regime in December 2024. The SDF, under its commander-in-chief Mazloum Abdi, had signed an integration agreement with Sharaa in March 2025, pledging to integrate all SDF fighters and affiliated civilian institutions into the new Syrian army and central government by the end of 2025. The deadline wasn’t met. Sharaa was adamant that all SDF units completely disband and that their ex-fighters join the new army as individuals. The SDF insisted its unique unit structures remain intact during integration. Unlike the other poorly disciplined ragtag ex-rebel groups that make up much of the new Syrian security forces, the SDF has U.S.-trained, battle-hardened counter-terror units with immense experience fighting ISIS. They would prove absolutely invaluable for protecting Syria from another ISIS resurgence.

Not long after the deadline passed, Syrian government forces routed the SDF in two Kurdish-majority neighborhoods in Syria’s second city, Aleppo, after five days of fighting in which they used heavy weapons in those urban areas. They triumphantly advanced westward, and fighting quickly spread east of the iconic Euphrates River, the heartland of Syrian Kurdistan, known in Kurdish as Rojava, or Western Kurdistan. These advances have once again seen Kobani under siege. The SDF’s political wing, the Syrian Democratic Council, accurately noted that the city represents “a global symbol of resistance against Daesh and the starting point of the organization’s collapse,” using another term for the group.

“Attacking Kobani is an attack on liberal and democratic values,” it said in a statement released Tuesday. “It is an act of revenge against those who shattered terrorism.”

The Syrian military offensive against the SDF has predictably empowered ISIS, as previously warned months ago in this space would happen if Damascus resorted to force to disband the Kurdish-led fighting force. Already, there are signs the violent group could rebound and reorganize amidst this chaos. The SDF withdrew from the enormous al-Hol camp in the northeastern Hasaka province that still holds thousands of ISIS family members and sympathizers on Tuesday, amidst clashes with the government forces. It angrily denounced “international indifference toward the issue of the ISIS terrorist organization,” in a statement on X, adding that its forces were “compelled to withdraw” from that notorious camp “and redeploy in the vicinity of cities in northern Syria.”

ISIS prisoners previously attempted a sophisticated, coordinated jailbreak from the SDF-controlled al-Sina’a prison in Hasaka city in January 2022, which took the SDF more than a week to suppress with U.S. support. On Tuesday, Iraqi Kurdistan’s Rudaw Media Network reported that the SDF-run al-Aqtan prison in Syria’s Raqqa province came under fire from government forces, raising fears that its approximately 2,000 ISIS inmates could escape. Furthermore, SDF spokesperson Farhad Shami told the same outlet that approximately “1,500 ISIS militants – including both foreign and Syrian nationals – have been released” by government-aligned armed groups from Hasakah’s al-Shaddadi prison, which the SDF lost control of on Monday.

For years, the SDF controlled and administered several Arab-majority cities captured from ISIS, such as that group’s de facto capital city, Raqqa, and Deir ez-Zor. With these now falling to the new government’s forces, it appears the Kurdish-led group calculates that it can hold out in Kurdish-majority cities such as Kobani and Qamishli. Many Kurds outside Syria have protested against the Syrian action, fearful that this minority could end up subjected to massacres by government forces or government-affiliated militias, as already happened to the Alawite and Druze minorities in 2025. These earlier massacres also made the SDF hesitant about completely disbanding immediately, as Sharaa continues to demand.

What happens next is anyone’s guess, but what’s at stake could hardly be any clearer. Kurds have expressed understandable feelings of betrayal from the U.S. In October 2019, President Donald Trump invoked accusations of betrayal when he suddenly ordered the complete withdrawal of U.S. troops from Syria, leaving the SDF to face an immediate cross-border Turkish invasion alone. The withdrawal was ultimately postponed amidst the ensuing instability. Ahead of his second term, the SDF expressed some guarded optimism that they could negotiate a peaceful solution with Damascus under President Trump.

U.S. troops regularly worked with the SDF over the years. And the SDF even protected American troops, which were always deployed in Syria in small numbers. The last time ISIS managed to kill Americans in Syria was in the Arab-majority town of Manbij in January 2019. Almost immediately after U.S. troops began anti-ISIS patrols with Syria’s new military, three were shot dead by an ISIS sympathizer who had managed to infiltrate the security forces in December 2025, raising serious questions about the vetting process for the new military.

If fighting continues, the most effective counter-terrorism forces in Syria may soon be dismantled or outright destroyed, and thousands of ISIS militants and sympathizers freed, which preliminary reports suggest might already be underway. With the SDF out of the equation and the recurring incompetence, indiscipline, and outright lawlessness exhibited by Syria’s new military, it’s hard to see who stands in the way of ISIS plotting new attacks against civilians across Europe like it did when it still had its caliphate a decade ago.