https://crsreports.congress.gov
Updated August 3, 2023
Syria Conflict Overview: 2011-2021
Through 2021, conflict in Syria had persisted for a decade,
and had displaced approximately half of the country’s pre-
war population. This product provides a historical overview
of the conflict through 2021. As of 2023, five outside
countries regularly operate in or maintain military forces in
Syria: Russia, Turkey (Türkiye), Iran, Israel, and the United
States—as well as the U.S.-backed Syrian Democratic
Forces and transnational terrorist groups such as the Islamic
State, Al Qaeda (AQ), and Lebanese Hezbollah.
2011: Protests Emerge
In March, antigovernment protests broke out in Syria,
which has been ruled by the Asad family since 1971. Two
umbrella opposition groups emerged—one political, one
armed—with the leadership of both based primarily in
exile. Political groups established the Syrian National
Council (SNC), while military defectors formed the Free
Syrian Army (FSA), which claimed leadership over the
armed opposition but whose authority was generally
unrecognized by local armed groups. Escalating violence
prompted President Obama in August to call for President
Bashar Asad to leave power. Meanwhile, the Islamic State
of Iraq sent members to Syria to operate as a new group
called the Nusra Front.
2012: Insurgency
The conflict became increasingly violent, as Syria began to
use artillery and fixed wing aircraft against opposition
targets. Extremist attacks became more frequent, and in
February the United States closed its embassy in Damascus,
citing security concerns. Armed groups began to seize
territory throughout Syria, primarily in rural areas, while a
bombing in Damascus killed several senior regime officials.
The United States and Russia signed the Geneva
Communiqué, which called for the establishment of a
transitional governing body in Syria with full executive
powers, and has been the basis of U.N.-sponsored talks
between the government and the opposition. Syria’s
political opposition settled into its present form as the
National Coalition of Syrian Revolutionary and Opposition
Forces—aka the Syrian Opposition Coalition (SOC), or
Etilaf in Arabic. The United States began non-lethal aid to
bolster some opposition groups. In August, President
Obama declared that the use of chemical weapons would be
a “red line” for the United States.
2013: Proxy War, ISIS, Chemical Attacks
In March, opposition forces seized the city of Raqqah.
Subsequent opposition victories in the area led the
government effectively to concede control of Syria’s rural
northeast. Opposition victories prompted increased
involvement by external allies of the Syrian government—
Lebanese Hezbollah, Iran, and Russia—to bolster the Asad
Figure 1. Syria
Source: CRS, using ESRI, and U.S. State Department data.
regime; the United States, Turkey, and some European and
Arab Gulf states increased their support to the Syrian
opposition. U.S. allies differed in their goals and strategies,
and thus in their support for various opposition factions. ISI
leader Abu Bakr al Baghdadi announced the merger of ISI
and the Nusra Front into the Islamic State of Iraq and Al
Sham (ISIS/ISIL). In August, a Syrian government attack in
Ghouta using the nerve agent sarin killed an estimated
1,400 people. President Obama requested congressional
approval of a limited authorization for the use of military
force to respond. Congress debated, but did not authorize
the request. President Obama withdrew the request after
Syria agreed to a joint U.S.-Russian proposal to join the
Chemical Weapons Convention, dispose of its declared
chemical weapons stockpiles (completed in 2016) and
destroy declared production facilities (completed in 2018).
2014: Operation Inherent Resolve Begins
In February, Al Qaeda severed ties with ISIS. ISIS seized
vast stretches of territory in Syria and Iraq, and in June
declared a caliphate with its capital at Raqqah. The group
changed its name to the Islamic State (IS), and thousands of
additional foreign fighters traveled to Syria and Iraq to join
its ranks. In July, the U.N. Security Council adopted
Resolution 2165, authorizing cross-border aid into
opposition-held areas of Syria. In September, the United
States began air strikes against IS targets in Syria, pursuant
to the 2001 and 2002 Authorizations for Use of Military
Force (AUMF); officials stated the Islamic State was a
direct derivative of Al Qaeda. A subsequent air campaign to
lift the IS siege on the town of Kobane brought the United
States into partnership with the Kurdish People’s
Protection Units (YPG). Also in September, Congress
