Aleppo is a city on edge. Shelling pounds the key battleground daily, an unrelenting and terrifying reminder of Syria’s five-year civil war. Earlier this month, President Bashar al-Assad’s regime cut off access to the main road from Aleppo to the Turkish border, in turn hampering any movement by rebels fighting his government but also NGOs who are trying to bring supplies to the city’s beleaguered populace. The Russians and Iranians ...