The rebels’ focus on smaller, vulnerable regime targets has allowed them to gain control of stronger regime positions that their current military capabilities cannot directly defeat. Though the rebels control large swaths of territory, they have never been able to capture large military bases. Attacks focus instead on convoys, checkpoints, and combat outposts, which in turn force the regime to abandon otherwise strong positions. Employing this indirect approach is the key to the rebels gaining control of the northern cities.
The rebels have not demonstrated the ability to capture strong regime positions like military bases or large cities. They have, however, been able to force the regime to pay a major price for traversing the northern roads by employing IEDs and ambushes. The regime reevaluated the value of maintaining isolated positions, and in two recent cases in al-Bab and Bab Hawa, decided to withdraw. The rebels were not able to drive the regime out through a pitched battle, but by making the cost of resupply prohibitively high, the rebels have pushed the regime out of heavily defended, but isolated positions.
When the dust settles in the north, the regime will likely be in control of the cities of Idlib and Aleppo as well as scattered checkpoints and bases, but not the roads. If the rebels improve their IED capabilities and focus on ambushing convoys on the M5 highway between Damascus and Aleppo, as well as the M4 highway between Saraqeb and the coast, while maintaining pressure on Damascus, they may force the regime to make the same decision it made in al-Bab and Bab Hawa. The rebels do not have to take the cities by force or even entirely cut off the roads. They simply have to make resupplying the north so costly that the regime is forced to abandon the effort in order to focus on securing Damascus and Homs.