Having taken the Mallah Farms, a strategic area north of Aleppo, the loyalist strike force is about 2 kilometers (1.2 miles) from the Castello Road, the last remaining supply line into the rebel-held areas. Heavy shelling and airstrikes on the road have made it too dangerous for vehicles to brave, effectively cutting the rebels off. The battle to besiege the rebel positions has been particularly fierce over the past few months, and loyalist forces have paid for their advance toward the Castello Road with heavy casualties. Their latest attempts, made with top combat units supported by heavy Russian airstrikes, have made considerable progress against the weakened rebel defenses.
Originally, U.S.-backed fighters, many from the Fatah Halab and Nour al-Din al-Zinki units, exclusively manned the defenses in the area. This arrangement followed an agreement with the United States and its allies that sought to separate those units from other, more extreme rebel groups such as Jabhat al-Nusra, al Qaeda's branch in Syria. But as the loyalist offensives progressed, the rebel units felt as if they had no choice but to call on Jabhat al-Nusra for reinforcement. With the group's support, the rebels launched fierce counterattacks and halted the loyalists' advances. The Syrian government and its allies, however, still hold the upper hand in the battle.
Though the intermixing of Jabhat al-Nusra and the more moderate rebel forces in Aleppo has been a success on the battlefield, it will undoubtedly complicate the search for an understanding between the United States and Russia in Syria. During a telephone conversation on July 6, Russian President Vladimir Putin and U.S. President Barack Obama agreed to increase coordination of military action in Syria, including in the fight against Jabhat al-Nusra.
The United States, keen to avoid seeing the sizable rebel contingent in the city hemmed in, will push for a cessation of hostilities in the area and may even suggest designating it as a no-strike zone for Russian and loyalist aircraft. But the Russians will argue that since Jabhat al-Nusra is now present in the city in force, per the recent agreement, the United States should not only allow Russian airstrikes but also possibly participate in them. Given the desperate state of the battle, the rebels are likely beyond the point where they could ask Jabhat al-Nusra to leave their lines, despite the threat of continuing Russian airstrikes. Jaish al-Fatah, the most capable rebel coalition in which Jabhat al-Nusra figures prominently, is now indispensable to the rebel effort to prevent a full loyalist encirclement of Aleppo.
A key part of the July 6 deal between the United States and Russia is that the Russians will persuade Damascus to halt its airstrikes. This stipulation rests on the assumption that the Russians, given their enormous influence in Damascus, can actually get the Syrian government and its loyalist forces to play along. But even the United States admits that this is a long shot. Iran arguably wields more influence in Syria, considering its historical involvement and enormous contributions to the loyalist side, and Tehran will undoubtedly undermine any proposal that it deems hostile to its objectives in the country.
Russia's interests may be best served by using the latest battle as a pressure point to force more concessions from the United States. But in light of the enormous price they have paid so far in Aleppo, the Syrian loyalists and their Iranian allies are unlikely to cede their considerable military advantage just to please Russia. They also will have to be convinced that the ultimate agreements will favor them, an uncertain prospect at this point.