The video shows the attack on Palmyra, the historic Syrian city reclaimed from Isil for the Assad regime, and as a column of troops heads across the desert behind him a soldier is giving a commentary.

“Despite many casualties, they are moving forward in the advance,” he says.

The oddity is that he is not speaking Arabic, but Persian. The man himself is Afghan, a member of a 10-20,000-strong Afghan army recruited in Iran to fight the war in Syria.

The reconquest of Palmyra was presented to the world as a victory for President Bashar al-Assad’s Syrian Arab Army.

As Islamic State jihadists fled, regime troops forced their way into the town, known for its celebrated Roman ruins. Everyone from Russian apparatchiks to British conservative politicians congratulated Mr Assad for reclaiming the town for civilisation.

The role of the Russian air force in preparing the way for the ground advance was noted: this was the anti-Isil alliance promised at the start of Russian military intervention in Syria but which in practice seemed slow to make gains.

• First pictures from inside the recaptured city of Palmyra

In fact, it is now clear it was an eccentric multinational force that took Palmyra. Analysis of photographs, social media posts and Iranian, Russian and even Syrian media has shown that the path was led by the Russians, with much of the “grunt” work done by Afghan Shia and Iraqi militiamen under generals from the Iranian Revolutionary Guard.