On Syrian frontline, Russia's war on Ukraine evokes painful memories

Damaged buildings are pictured along a deserted street in the rebel-held town of Tadef, on a frontline between Russian-backed Syrian government forces and Turkey-backed Syrian rebel-held territory, in northern Syria March 4, 2022. Picture taken March 4, 2022. REUTERS/Khalil Ashawi

Using trench and tunnel warfare, Syrian rebel fighter Abu Ahmad said he and his group held out for years against government forces in eastern Ghouta until Russian air power came to President Bashar al-Assad's aid in 2015, to devastating effect.

As he follows the news from Ukraine, Abu Ahmad is reminded of the pivotal role Moscow played in turning the tide of the conflict in favour of Assad and against rebels seeking to topple him, using siege warfare and ferocious bombardment.