Timeline of the Syrian Civil War (September–December 2018)
- Russia and Turkey announced a demilitarized zone in Syria's Idlib Governorate and ruled out any military operations.
- Several missiles are launched from the sea by Israeli Air Force at the coastal city of Latakia, some of which are destroyed by air defence systems. A Russian Air Force Ilyushin Il-20 reconnaissance plane with 15 servicemen on board crashes over the Mediterranean Sea during the incident. The plane was shot down by Syrian air defense systems trying to target hostile aircraft.
- Israeli defense minister Avigdor Lieberman claims Israel will continue conducting strikes into Syria despite the recent arrival of Russia's S-300 anti-missile system.
- Syrian President Bashar al-Assad told a little-known Kuwaiti newspaper Al-Shahed that Syria had reached a "major understanding" with Arab states after years of hostility over the country's civil war.
- United States Secretary of Defense Jim Mattis announces the U.S. will set up new observation posts along the Turkish border in northern Syria in order to reduce skirmishes between Turkish forces and armed Kurdish militants in the region such as the October 31 incident. Mattis affirms it is a co-operational endeavor with Turkey and it will not require additional US troops to be deployed to Syria.
- Syrian government officials accuse Idlib-based rebels of a suspected poison gas attack on Aleppo after Syrian state TV aired footage of more than 50 civilians being admitted to a local hospital for breathing problems and blurred vision following alleged shelling. The rebels would deny the attack, claiming to not possess poison gas nor the ability to launch projectiles of it; instead they accused the government of attempting to undermine the ceasefire.
- Turkey says the Syrian government and rebels conducted a 20-man prisoner exchange near al-Bab, calling it the "first important step" of a joint Russia-Iran-Turkey-brokered peace process.
- The US-led Coalition establishes its first observation post along the Syrian-Turkish border in Tal Abyad. Local security sources state that there will be three total posts in Tal Abyad and two in Kobani.
- The US's Federal Aviation Administration extends its no-fly rule over Syrian airspace for commercial and private flights by American air carriers until December 2020.
- The Syrian army general command orders the demobilization of some conscript and reserve officers that have served multiple years during the civil war.
- The Syrian Observatory for Human Rights reported a large number of local civilians and tribesmen from the Khasham and New Akidat area clashed with guards of the US-backed Syrian Democratic Forces (SDF) and managed to capture several oil wells in the Conoco oil field after SDF personnel allegedly avoided supplying fuel to the village of New Akidat and refugee camps in the region while hoarding fuel for themselves, causing local prices to spike.
- Despite recent apparent attempts by the US to dissuade violence in northern Syria, Turkish President Tayyip Erdogan announced Turkey will launch a new military operation targeting US-backed Kurdish territory (DFNS) east of Manbij "in a few days".
- Proclaiming ISIL's defeat, US President Donald Trump orders the deliberate withdrawal of all of the approximately 2,000–2,500 American troops from Syria "within 60–100 days". Reuters reports the move comes after a phone call between Trump and the Turkish President Erdogan. French forces are to remain.
- With the previous announcement of the withdrawal of US troops, Iraq's Prime Minister Adil Abdul-Mahdi says Iraqi troops could potentially be deployed to Syria.
- In the face of the planned withdrawal of US forces and the Turkish preparations to attack the DFNS, the SDF handed over the town of Arima west of Manbij to troops of the Syrian government.
- Three days after handing over Arima to the Syrian army amid the continued mobilization of Turkish regular and Turkish-backed Free Syrian Army forces, conflicting reports emerged surrounding the YPG's inviting of Syrian troops to enter Manbij in order to deter the Turks from attacking the city. SOHR stated Syrian troops had deployed around the Manbij countryside while US-led Coalition officials denied that the SAA had taken Manbij as US forces continued to patrol in and around Manbij with no immediate plans to leave. In a future conflict, the Kurds want the Syrians to control Manbij, not pro-Turkish rebels. Turkey decried that the Kurds have no authority to make decisions on behalf of the region's people.
- SANA reports that Syrian President Assad authorized Iraqi warplanes and artillery to strike ISIL targets in Syrian territory without having to seek prior approval from Damascus, a sign of improved relations and coordination between the neighboring countries.
- "The Latest: French FM says Syria's Assad has 'won the war'". September 2, 2018.
- "The Netherlands stops supporting Syrian rebels, ahead of Idlib offensive – DutchNews.nl". September 10, 2018.
- "Russia claims there will be no Idlib offensive after agreement with Turkey to create military buffer zone".
- "In rare move, IDF admits Syria strike, expresses sorrow over Russian plane".
- "Syria shot down Russian military reconnaissance plane, admits Kremlin".
- "Syria Reopens Border Crossing with Jordan".
- "Israel will continue strikes in Syria despite S-300 missile system delivery: Minister". October 3, 2018.
- "Syria's Assad Reaches 'Understanding' With Arab States". Voice of America. Associated Press. October 3, 2018. Retrieved October 4, 2018.
- i24NEWS. "Road to recovery: Syria opens two key crossings with Jordan, Israel". i24NEWS. Retrieved October 15, 2018.
- "Turkish military again shells Kurdish positions in Syria". Associated Press. October 31, 2018.
- "Turkish Forces Shell Northern Syria, Kurdish-Led Force Responds". Reuters. October 31, 2018.
- "US, Turkey begin joint patrols around northern Syrian town of Manbij". November 1, 2018.
- "Daesh suffers devastating defeat as Syrian Army liberates entire Al-Safa region". Al-Masdar News. November 19, 2018. Retrieved November 20, 2018.
- "The US military is putting brand new observation posts in northern Syria". November 21, 2018.
- "US to establish observation posts on Syria-Turkey border: Mattis". Rudaw Media Network. November 21, 2018.
- "Radio host who mocked Assad shot dead along with his colleague in Syria". November 24, 2018.
- "Raed Fares: Syria radio host shot dead in Idlib". BBC News. November 24, 2018.
- "Syria accuses rebels of poison gas attack in Aleppo". November 24, 2018.
- "Syrian rebels dismiss poison-gas claims". The Washington Post. November 24, 2018.
- "Syria regime and rebels swap prisoners, Turkey says". France 24. November 24, 2018.
- "Kurdistan 24 captures completion of first US observation post on Syria-Turkey border". Kurdistan 24. November 27, 2018.
- Afp. "Syria coalition says it killed IS leader linked to beheadings". The Sun. Malaysia. Retrieved December 17, 2018.
- "US-led coalition strikes Islamic State figure involved in killing American Peter Kassig". USA Today. Retrieved December 17, 2018.
- "FAA extends no-fly rule for US carriers over Damascus skies until December 2020". TASS. Retrieved December 17, 2018.
- "Syrian army demobilises some conscripted, reservist officers". Reuters. December 10, 2018. Retrieved December 17, 2018.
- "Syrian Civilians Seize Oil Wells From Rebel Group". OilPrice.com. Retrieved December 17, 2018.
- "Farsnews". en.farsnews.com. Retrieved December 17, 2018.
- "Turkey to Launch Operation Against U.S.-Backed Kurds in Syria 'In a Few Days'". December 12, 2018.
- "U.S.-backed fighters in Syria capture last town held by ISIS". December 14, 2018.
- Baldor, Lolita. "US to withdraw all American troops in Syria, official says". Fox News Channel. Retrieved December 19, 2018.
- "Erdoğan-Trump call resulted in US withdrawal from Syria: US official". Daily Sabah. December 19, 2018.
- France says it will continue to fight Islamic State in Syria
- "Turkey to clear Syria of both YPG, ISIL: Erdoğan". Hürriyet Daily News. December 21, 2018.
- "Russia offers to deploy border guards of the regime on the borderline between the two rivers and a delegation of SDF arrives in Moscow to discuss it and discuss the future of east Euphrates". SOHR. December 23, 2018.
- "Iraq Says It Could Deploy Military into Syria". VOA. December 24, 2018.
- "Breaking: Kurdish forces handover town near Manbij to Syrian Army". Al-Masdar News. December 25, 2018.
- "UAE reopens Syria embassy, a boost for Assad". Reuters. December 27, 2018. Retrieved December 27, 2018.
- Bahrain says embassy work in Syria continues after UAE move
- "Syrian army takes control of flashpoint Kurdish town threatened by Turkey". The Guardian. December 28, 2018.
- "Conflicting reports on Syrian entry into key Kurdish town of Manbij". CBS News. December 28, 2018.
- "Syria's Assad authorizes Iraqi forces to strike IS in Syria". The Washington Post. December 30, 2018.