U.S. troops have been on the ground in Syria for over a decade. Here’s the back story and present situation after the deadly Islamic State attack

The death of two U.S. service members and one American civilian in an attack in Syria by an alleged member of the Islamic State group has drawn new attention to the presence of American forces in the country.

Saturday’s attack was the first with fatalities since the fall of Syrian President Bashar Assad a year ago.

The United States has had troops on the ground in Syria for over a decade, with a stated mission of fighting IS. While not part of its official mission, the U.S. presence has also been seen as a means to hinder the flow of Iranian and Iran-backed fighters and weapons into Syria from neighboring Iraq.

The number of U.S. troops in the country has fluctuated and currently stands at around 900. They are mainly posted in the Kurdish-controlled northeast and at the al-Tanf base in the southeastern desert near the borders with Iraq and Jordan.

Here’s the back story and present situation of the U.S. military force in Syria:

What U.S. forces are doing in Syria

In 2011, mass protests in Syria against the Assad government were met by a brutal crackdown and spiraled into a civil war that lasted nearly 14 years before he was ousted in December 2024.

Wary of getting bogged down in another costly and politically unpopular war in the Middle East after its experience in Iraq and Afghanistan, Washington sent support to rebel groups but at first avoided direct military intervention.

That changed after the rise of the IS, which carried out sporadic attacks in the U.S. and Europe, while in Iraq and Syria, it seized territory that was at one point half the size of the United Kingdom. In the areas the group controlled, it was notorious for its brutality against religious minorities, as well as Muslims whom it considered to be apostates.

In 2014, the administration of then-U.S. President Barack Obama launched an air campaign against IS in Iraq and Syria. The following year, the first U.S. ground troops entered Syria, where they partnered with the Kurdish-led Syrian Democratic Forces in the country’s northeast.

By 2019, IS had lost control of all the territory it once held, but sleeper cells have continued to launch attacks.

The US military and Syrian forces

Before Assad’s ouster, Washington had no diplomatic relations with Damascus and the U.S. military did not work directly with the Syrian army.

That has changed over the past year. Ties have warmed between the administrations of U.S. President Donald Trump and Syrian interim President Ahmad al-Sharaa, the former leader of an Islamist insurgent group Hayat Tahrir al-Sham that used to be listed by Washington as a terrorist organization.

In November, al-Sharaa became the first Syrian president to visit Washington since the country’s independence in 1946. During his visit, Syria announced its entry into the global coalition against the Islamic State, joining 89 other countries that have committed to combating the group.

While the entry into the coalition signals a move toward greater coordination between the Syrian and U.S. militaries, the Syrian security forces have not officially joined Operation Inherent Resolve, the U.S.-led military mission against IS in Iraq and Syria, which has for years partnered with the Kurdish-led Syrian Democratic Forces in northeast Syria.

The future US footprint in Syria

The number of U.S. troops posted in Syria has changed over the years.

Trump tried to withdraw all forces from Syria during his first term, but he met opposition from the Pentagon because it was seen as abandoning Washington’s Kurdish allies, leaving them open to a Turkish offensive.

Turkey considers the SDF a terrorist organization because of its association with the Kurdistan Workers’ Party, or PKK, which has waged a long-running insurgency in Turkey.

The number of U.S. troops increased to more than 2,000 after the Oct. 7, 2023, attack by Hamas in Israel, as Iranian-backed militants targeted American troops and interests in the region in response to Israel’s bombardment of Gaza.

The force has since been drawn back down to around 900, but Trump has given no indication that he is planning a full withdrawal in the near future.

After Saturday’s attack, U.S. envoy to Syria Tom Barrack posted on X: “A limited number of U.S. forces remain deployed in Syria solely to finish the job of defeating ISIS once and for all.”

The U.S. presence “empowers capable local Syrian partners to take the fight to these terrorists on the ground, ensuring that American forces do not have to engage in another costly, large-scale war in the Middle East,” he said, adding, “We will not waver in this mission until ISIS is utterly destroyed.”

This story was originally featured on Fortune.com