The Syrian army has broken a 28-month siege by the Islamic State group on the city of Deir al-Zor, a strategic oil hub on the Euphrates river in the east of Syria.
Ahead of the ground assault by Syrian troops backed by Iran-sponsored Shia militiamen, a Russian ship based off the Syrian coast fired cruise missiles at Islamic State positions, opening the way for the advance.
The troops linked up with the government-held air base known as Brigade 137 on the outskirts of Deir al-Zor city, liberating the 7,000-strong garrison and the 90,000-100,000 civilians in adjacent residential neighbourhoods who had been sustained by air drops of supplies. A convoy of foodstuffs was dispatched to the city on Wednesday.
Syrian president Bashar al-Assad hailed the city’s defenders for standing their ground and protecting unarmed civilians, while praising the troops who broke the siege.
After lauding the victory, Russian president Vladimir Putin pledged Moscow's support for the effort to drive Islamic State, also known as Isis, from the rest of the Sunni city, which is a gateway to Iraq.
This campaign involves wresting areas held by Isis from 10,000 of its veteran fighters, who have laid mines and booby-traps and dug tunnels and bunkers in the city, and could use the 10,000 civilians under their control as human shields.
Since early 2016, Deir al-Zor has been a refuge for the Islamist group’s commanders and fighters fleeing offensives against Isis-conquered areas in Syria and Iraq.
The flow from Iraq of fugitive Isis fighters, armoured vehicles and weapons began after the fall of Ramadi, Falluja, and Tikrit in the west of the country and swelled once Baghdad's forces mounted assaults on Mosul and Tal Afar in the north.
The US-backed and Kurdish-led Syrian Democratic Forces are battling Isis in its de-facto capital, Raqqa, northwest of Deir al-Zor, but have not been able to prevent the group's jihadis from fleeing, although Russian warplanes have barred them from reaching Deir al-Zor city.
Fugitives have reached smaller Isis-occupied pockets of territory in the province of the same name.
Islamic State’s founder, Abu Bakr al-Baghdadi, is believed to be hiding somewhere near the Syrian-Iraqi border. Once the border province is back under Syrian government control, Isis will lose its last major territorial base.
Strategic victory
The return to Syrian government control of Deir al-Zor city and large swathes of territory in the province amounts to a major strategic, moral and psychological victory. Damascus has won the race to free the city ahead of the Syrian Democratic Forces, which Washington had hoped would secure control of the province.
In recent months, large swathes of territory elsewhere in Syria have been clawed back by the Syrian regime from jihadi and insurgent groups, complementing gains in urban areas, where 80 per cent of the Syrians residing in the country now live.
The Deir al-Zor victory could encourage internally displaced persons and refugees to return home to Syria, augmenting the 600,000 who have already done so. Ahead of last week’s Muslim holiday of Eid al-Adha, tens of thousands of refugees streamed across the Turkish border to survey the situation in Syria before deciding whether to stay.
Since the launch in May of the campaign to recapture Deir al-Zor city, 461km east of Damascus, the Syrian army has secured nearby oil and gas fields, depriving Isis of fuel and a main source of revenue.
The army also recaptured al-Sukhna, the last major Isis-held town in Homs province, and advanced against the group in Hama and Raqqa provinces, as well as in the Qalamoun mountains on the Lebanese border to the west, demonstrating the ability of pro-government forces to fight on several fronts simultaneously.
These gains are likely to strengthen Damascus's position if talks between the government and armed groups resume in Kazakhstan next week and UN-sponsored peace talks reconvene in Geneva in October.