The Washington Post reports: Syria’s government hopes a brutal siege will vanquish rebel holdouts in the city of Aleppo, a key battleground. But Syrian President Bashar al-Assad’s troops aren’t leading the charge.

That task has been taken up by thousands of Shiite militiamen from Lebanon, Iraq, Pakistan and Afghanistan who are loyal to Iran, a Shiite country and perhaps Assad’s most important ally.

For much of Syria’s civil war, these religiously motivated fighters have reinforced Syria’s badly weakened military. Now, they are playing an increasingly critical role in trying to seize opposition-held eastern Aleppo by coordinating their attacks with government forces and warplanes flown by Russia, another ally of Assad’s.

The government, backed by Russian aircraft, launched a major offensive across northern Syria last week that has brought further devastation to eastern Aleppo, Syria’s largest city before the war.

The militias appear to be forming a sophisticated ground coalition that has further bolstered Iran’s influence in Syria, alarming even officials in Assad’s government, said Phillip Smyth, an expert on Shiite militias at the Washington Institute for Near East Policy.

“They are building a force on the ground that, long after the war, will stay there and wield a strong military and ideological influence over Syria for Iran,” he said. “And there is not much Assad can do to curb the rising influence of these groups, even though Syrian officials are clearly concerned about this, because the militiamen are literally preventing the overthrow of his government.” [Continue reading…]