BEIRUT: US warships fired a volley of missiles at a Syrian airbase on Friday in response to a suspected chemical attack on April 4 that killed dozens of civilians.
It was the latest twist in a complex six-year civil war that has left Syria in ruins.
The conflict began with peaceful protests against the regime of President Bashar al-Assad in March 2011. Security forces bloodily repressed the demonstrations, prompting an armed rebellion.
The war has left more than 320,000 people dead, according to the Syrian Observatory for Human Rights.
Revolt and repression
March 15, 2011
Unprecedented protests demand civil liberties and freedom for political prisoners after 40 years of repressive rule by the Assad family.
Denouncing “an armed rebellion by Salafist groups”, the regime represses demonstrations in Damascus and the southern city of Daraa but protests continue.
In July, defecting army colonel Riyadh al-Assad sets up the Turkey-based rebel Free Syrian Army (FSA). Islamist groups join the revolt.
March 1, 2012
Regime forces seize rebel-held the Baba Amr district of Syria’s third city Homs after 27 days of heavy shelling.
July 17, 2012
FSA fighters launch a battle for Damascus, but the government holds firm.
Allies enter the picture
The Iran-backed Lebanese militant group Hezbollah says it is fighting alongside government forces.
Iran boosts its military support for longtime ally Assad.
August 21, 2013
Rebel backer Washington accuses the regime of killing more than 1,400 people with chemical weapons in rebel-held districts near Damascus.
In September, the United States and Assad ally Russia agree a plan to eliminate Syria’s chemical weapons, averting punitive US strikes against the regime.
Obama had vowed to act if Syria crossed a “red line” by using chemical weapons. His failure to follow through upsets allies such as France and Saudi Arabia.
Coalition air strikes
In September 2014, US President Barack Obama vows to build an international coalition to defeat IS.
Later that month, the US and its allies launch air strikes against IS in Syria.
The strikes benefit Kurdish groups, which in 2013 declared autonomous administrations in Kurdish-majority areas.
In January 2015, coalition-backed Kurdish fighters oust IS from the flashpoint border town of Kobane.
September 30, 2015
Russia launches air strikes in support of Assad. Moscow says it is targeting “terrorist groups” including IS.
The regime, on the back foot since March 2015, begins to retake territory.
August 24, 2016
Turkey launches a cross-border incursion — Operation Euphrates Shield — to tackle both IS and Washington-backed Kurdish militia Ankara considers “terrorists”.
Regime retakes Aleppo
September 22, 2016
The army announces a major offensive to retake rebel-held east Aleppo. Syria’s second city had been divided between rebels and government forces since 2012.
December 22, 2016
The army declares it is in full control after a final convoy of civilians and rebel fighters leaves under a pullout deal.
Ceasefire and talks
December 29, 2016
Russian President Vladimir Putin announces a nationwide ceasefire, saying warring parties will meet for Russian, Turkish and Iranian-backed talks.
Pressure on IS
In early November 2016, a US-backed Kurdish-Arab alliance targets Raqa, the Syrian heart of IS’s so-called caliphate.
Ankara is hostile to the idea, fearing Kurdish gains in Syria could embolden Kurds in Turkey.
Alleged chemical attack, US response
On April 4, 2017, a suspected chemical attack kills 86 civilians, including 27 children, in rebel-held Idlib province. Western governments accuse Assad of using banned weapons, which Damascus and Moscow deny.
Three days later, a retaliatory barrage of US cruise missiles hits an airbase in central Syria. US officials say Russia was given prior warning.