Loyalist forces continue to make notable gains in the ongoing offensive, having captured the villages of Kafr al-Saghir and Moqbila in the past 10 days, and they continue to advance on the rebel-held infantry academy. Ever since the loyalists reached the Aleppo central prison in late May, the regime has increasingly been able to threaten important roads running from the Turkish border into rebel-controlled portions of the city. Having all but taken the Brej roundabout and the Sheikh Najjar industrial district, loyalists will be in a position to effectively seal off rebels in the city if they can fight their way through the rebel-held district of Owaija and the Kurdish district of Sheikh Maqsood.
Fully aware of this growing threat, the rebels have had to scale back their own offensive, which centered on the air force intelligence building in western Aleppo, in order to shift reinforcements eastward. The rebels have begun counterattacks to halt loyalist advances, but with Republican Guard and Hezbollah reinforcements reportedly on their way, the situation is looking increasingly bleak for the rebels.
As has been characteristic of much of the battle of Aleppo, advances by either side have been slow and extremely costly, especially given the urban terrain and the abundance of defensive positions. This has given the rebels some time to continue with their gains in Idlib, Daraa and Quneitra as the regime focuses more on Aleppo. If the rebels lose Aleppo, however, their advances elsewhere will not do much to soften the psychological and logistical blow — and potential loss of manpower — that would come from the loss of such an important city.
Depending on its plans and movements, the Islamic State can also play a critical role in Aleppo. For the moment, the Islamic State appears to be focused on eliminating the pocket of Kurdish forces concentrated in the border city of Ayn al-Arab. Heavy battles with the Kurdish People's Protection Units over the past week have already inflicted heavy casualties on both sides, and Kurdish fighters from Iraq and Turkey are reportedly on their way to Syria to defend against the Islamic State's attacks. From its position at al-Bab, however, the Islamic State can also push westward more forcefully into rebel-held territory in northern Aleppo. Such a move could sever supply lines into the city and require the rebels to divert forces to face this new threat.
It is not entirely surprising that the regime has allowed a rebel unit, the Dawud Brigade, to cross its territory unharmed in a convoy of approximately 50 vehicles after it defected to the Islamic State. From its positions around the town of Sarmin in Idlib province, the Dawud Brigade swung east and north into Raqqa province, through the critical regime supply lines running from Khanasir to Aleppo, without regime interference. Though loyalist fighters continue to clash with the Islamic State on multiple fronts, the regime has attempted to take advantage of every instance of rebel infighting. The transfer of more Islamic State forces into Raqqa and potentially northern Aleppo only increases the threat to the rebel rear during the battle for the city.
The rebels in Aleppo appear determined to hold on to what they have gained, but with growing regime pressure on their supply lines and with the growing threat of the Islamic State to their rear, it is becoming increasingly difficult for them to prevent the encirclement of their forces in the city. While the battle is far from over, the rebels' lack of support and the multiple threats they face have put them in a desperate position. The evolution of the battle for Aleppo is a critical indicator of the status of the conflict in Syria, and the fall of the city, should it occur, would swing the momentum of the conflict squarely in the regime's favor.