As insurgent offensives stalled near Benghazi and Misurata, fighters made up of Arabs and ethnic Berbers, or Amazigh, tenaciously gained ground in the west. There is no indication the western fighters possessed superior firepower or were better trained than their undisciplined comrades in the east. But geography was certainly an ally.
In the east, rebels struggled to move forward in flat desert terrain that proved advantageous for Kadafi’s artillery and rocket launchers, often well concealed from allied aircraft. In contrast, the western fighters engaged in a guerrilla war on turf that was intimately familiar to them. Supplies arrived via a captured post on the Tunisian border.
By June, the mountain fighters had largely gained control of the highlands and were filtering into the plains that led to the coast and the capital, the ultimate prize. Tribal links to lowland populations probably aided their advance. Government officials in Tripoli betrayed no sense of alarm.