Syria’s long civil war has again captured the world’s attention after rebels seized its largest city and dozens of surrounding towns and villages.
The surprising advance by rebel forces on Aleppo came as several key players in the conflict were distracted or weakened, leading to the heaviest clashes since a 2020 ceasefire brought relative calm to the country’s north.
Russian and Syrian forces carried out dozens of airstrikes to limit the rebel advance, causing heavy casualties.
Syria’s civil war began in 2011 after an uprising against President Bashar Assad’s rule. Five foreign powers have a military presence in the country, including the United States, Russia and Iran. Forces opposed to Assad, along with US-backed fighters, control more than a third of the country. Israel holds the Golan Heights, which it seized in a 1967 war with its Arab neighbors.
Here’s a look at the major players:
Syrian government troops have long controlled a large part of the country thanks to allied forces sent by Russia and Iran.
Assad’s forces control most major population centers, including the capital Damascus and cities in Syria’s center, south and east.
The Syrian government’s capture of Aleppo in late 2016 was a turning point in the conflict and losing the city in recent days is a major setback.
Iran’s military advisers and proxy fighters have played a key role in bolstering Assad’s forces throughout the war. But Lebanon’s Hezbollah militant group, which is backed by Iran, has been weakened in its recent war with Israel and Iran has been distracted by the conflict. On Monday, Iran-backed Iraqi militias deployed to Syria to support the government’s counteroffensive.
Russia’s military has supported Assad off the Mediterranean coast, where it maintains its only naval base outside the former Soviet Union, and at the Hmeimim air base in Latakia province, where hundreds of Russian troops are based. But much of its attention and resources have been focused on its war in Ukraine.
Anti-government forces are led by the rebel Hayat Tahrir al-Sham, which has long operated as al-Qaeda’s branch in Syria and is considered a terrorist group by many countries, including the United Nations and the United States.
HTS controls much of northwestern Syria and in 2017 established a “salvation government” to run day-to-day affairs in the region. In recent years, its leader Abu Mohammad al-Golani has tried to rebuild the group’s image, breaking ties with al-Qaeda, abandoning hardline officials and vowing to embrace pluralism and religious tolerance.
Other rebel groups include Nureddin al-Zinki, which was previously backed by the US but later joined the HTS-led coalition.
A coalition of Turkish-backed groups known as the Syrian National Army has attacked several areas, including the northern town of Tel Rifaat, which is controlled by the US-backed and Kurdish-led Syrian Democratic Forces.
Chinese fighters from the Turkistan Islamic Party and Chechen fighters from the former Soviet Union are involved in the fighting in the country’s northwest, according to Syrian opposition activists. Turkey, which controls parts of northern Syria, would not say how many troops it has in the country.
The Kurdish-led Syrian Democratic Forces, a coalition of US-backed groups, controls large parts of eastern Syria.
The SDF has battled the Islamic State group, and has recaptured the last bit of land held by the extremists in eastern Syria. About 900 US troops are deployed in Syria’s east to avoid a resurgence of the extremist group.
SDF forces still control several areas of Aleppo besieged by rebels. Opposition activists have said rebels are willing to let those fighters move into northeastern Syria, but it was not immediately clear whether the Kurdish-led force would do so.
Turkey believes the SDF’s main Kurdish faction is linked to the banned Kurdistan Workers’ Party, or PKK, which it and its allies regard as a terrorist group.