US President Joe Biden was quick to thank the Syrian Democratic Forces on Thursday for their help in the commando raid that ended in the death of ISIS leader Abu Ibrahim Al Hashimi Al Qurayshi.
Founded in 2015, a few years into Syria's civil war, the SDF are a mostly Kurdish fighting force that has played an instrumental role in combating ISIS.
With considerable US support, the SDF formed as the military wing of the Autonomous Administration of North and East Syria, often referred to as Rojava. The forces initially consisted of People’s Defence Units (YPG) soldiers and elements of the Free Syrian Army.
While predominantly Kurdish, the group has many Arabs, Assyrians and Armenians in its ranks, and it is known for including women in its fighting components.
For years, the SDF waged a brutal war against ISIS and the Pentagon relied heavily on the group as a key ally in the fight, with US trainers instructing SDF members on how to call in air strikes.
With support from the US-led coalition, the group in 2017 retook Raqqa, ISIS's main stronghold in Syria.
In 2019, again with coalition support, the SDF mounted a months-long siege on Baghouz, the last main holdout for ISIS in Syria.
After six weeks of intense fighting and shelling, the SDF defeated ISIS, officially ending the group's claims to a caliphate, which at its peak covered one third of Syria and Iraq.
“They really are important,” said Nathan Sales, an ambassador-at-large who served as co-ordinator for counterterrorism under former president Donald Trump.
“They've shed a lot of blood and borne a lot of the costs of the coalition's efforts against ISIS.”
Mr Sales said without the efforts of the SDF, it is unlikely the US would have been as successful in destroying the so-called caliphate.
While ISIS has been territorially defeated, the SDF remains at the forefront of a counter-terrorism battle against the group's remaining cells.
Last week, the SDF suppressed a prison break led by ISIS sleeper cells in Hassakeh.
After several days of intense fighting during which more than 120 SDF fighters and prison staff were killed, the SDF, with the help of US forces, regained control of the prison.
Former president Donald Trump in 2019 announced he would withdraw US forces from north-eastern Syria, a move the group saw as a betrayal after years of US support.
The decision outraged former Pentagon chief Jim Mattis, who resigned, and the US left hundreds of troops in Syria.
Recent events show the SDF continues to be a crucial ally in the international effort to defeat ISIS.
“We'll continue working with our close allies and partners, the Syrian Democratic Forces, the Iraqi Security Forces, including the Kurdish Peshmerga, and more than 80 members of the Global Coalition to keep pressure on ISIS to protect our homeland,” Mr Biden said on Thursday.
