Though the government controls Idlib city, Jabhat al-Nusra and its allies in Ahrar al-Sham pose one of the biggest threats to loyalist forces. The rebels have been able to effectively shut down the M5 highway leading to Aleppo, forcing loyalist fighters to carve out another supply line through more rugged terrain to sustain their offensive. There are a large number of isolated and besieged loyalist positions in Idlib, and loyalist forces have had to expend considerable manpower to try to break through the M5 corridor that leads to Aleppo in an attempt to relieve these stranded troops.
Daraa province, which has long been firmly under loyalist control, has steadily come under increasing threat over the past two years. Of particular note is the strength of the Free Syrian Army in the region, which works under the umbrella effort known as the Southern Front. Unlike the Free Syrian Army in the north and east, the more moderate rebels in the south have held their own and have steadily increased their power in Quneitra and Daraa. They have benefited greatly from short supply lines into Jordan and from a considerable amount of external support from the West and the Gulf Cooperation Council.
The Free Syrian Army is not the only faction with a presence in Daraa, however. Ever since the Islamic State drove Jabhat al-Nusra from Deir el-Zour, a significant number of the al Qaeda-affiliated fighters have made their way to Daraa, where they have maintained relatively friendly ties with operatives of the Free Syrian Army. Together these forces have scored significant battlefield victories, claiming more than 80 percent of Quneitra from loyalists and increasing pressure on loyalist forces in Daraa city. They have also seized important towns and military bases including those around Nawa in addition to fighting off loyalist assaults in Sheikh Miskin despite considerable Hezbollah support.
The Islamic State has seized the vast majority of Deir el-Zour province in eastern Syria. The government, however, continues to maintain a considerable military presence in Deir el-Zour city, including in the airport and military bases. Despite the logistical problems that arise from supplying their largely isolated forces there, the Syrian Arab Army continues to exert great effort to secure and expand their control in the province.