Iran and Russia, both stretched by conflicts of their own, have experienced setbacks in Syria after a rebel offensive in the northwest of the country.
Russian and Iranian support for Syria.
The group now advancing, Hayat Tahrir al-Sham, says it wants to replace the Assad government with one inspired by Islamic principles.
Rebel fighters entered parts of Aleppo on Friday, reigniting violence in the long-standing conflict.
Diminished support for the Syrian government from Iran, Hezbollah and Russia enabled opposition forces to take the initiative and seize new territory.
Plus, the vast network of undersea internet cables.
Syria's military rushed in reinforcements on Sunday to push back insurgents from advancing farther into the northern Hama countryside after they seized Aleppo.
Forces opposed to President Bashar al-Assad have captured the Aleppo airport and are attacking the western city of Hama, according to local officials and a Britain-based...
Rebel groups have launched the largest offensive in years against government forces in the northwest.
A war monitor and the rebels said the opposition fighters breached three neighborhoods in Aleppo. The government launched intense airstrikes on rebel territory.