As US cruise missiles struck a key air base near Homs, Syrian flags flew from public buildings to mark the 70th anniversary of the founding of the ruling Baath party. Instead of feeling optimistic about recent army advances, Syrians now fear the peace process is about to collapse.
These fears were reignited by Tuesday's apparent chemical weapons attack, which activists say killed 80 people in al-Qaeda-held Idlib province.
Friday's operation was the second by the US on a Syrian military installation. The first took place in September 2016, when US air strikes lasting an hour hit strategic army positions countering Islamic State in Deir al-Zor province in eastern Syria. At least 100 soldiers were killed and 110 wounded.
Although the US claimed that target was a mistake, Syria's ally Russia condemned the air strikes. Syria accused the US of aiding radicals entrenched in the province and it then rejected a ceasefire negotiated by the US and Russia, delaying a return to negotiations in Geneva.
This time the situation is far more serious. The US targeted the Shayrat air base near Homs, from where the Syrian air force mounts sorties against insurgent- and jihadi-held areas in Idlib, Hama, Homs and Palmyra. Taking out one of the most important of the government’s remaining air bases – although there are conflicting reports over just how damaged the base is – will weaken the fight against insurgents and strengthen Islamic State (also known as Isis) in the east and al-Qaeda in the west.
This could undermine the US campaign to defeat the jihadis and risk the collapse of Syria into entities ruled by al-Qaeda, Islamic State and other jihadis.
Russian exposure
While the US claims it took care not to hit Russian military facilities at the base, the exposure of Russian personnel and equipment to missiles has outraged Moscow and rendered impossible co-operation with Washington, which was once regarded by US president Donald Trump as essential for ending the war.
Moscow has reverted to its position that US military action in Syria is "illegitimate" and "aggression", since US intervention does not have the approval of Damascus. Consequently, Russia has suspended exchanges with the US of information about air operations in Syria, risking confrontations or accidents.
If the Russian-Turkish sponsored ceasefire is suspended because Moscow withdraws backing, the Geneva talks on a political settlement cannot continue and modest advances achieved this year will be lost.
The Riyadh-sponsored opposition High Negotiations Committee (HNC) celebrated the US strikes and reasserted its demand for President Bashar al-Assad’s removal. Adoption of this line by the Trump administration will leave no incentive for Damascus to negotiate. Moscow will cease pressing for talks and concessions.
Islamic State, al-Qaeda and other insurgent factions could take advantage of the loss of the Shayrat air base to launch fresh operations against the exposed Syrian army.
As news of the missile strikes broke, Damascus reported an Islamic State military probe in the Palmyra area. A Syrian activist from Aleppo who tweets under the name Edward Dark predicted jihadi organisations, which have previously used chemical weapons, could mount "false flag" attacks with the aim of implicating Damascus, in the expectation of further US intervention.