This was made even more challenging by the decision by the Terrans to liberally sprinkle the zone with Ion Mines during the early cycles of the war. While making it challenging for Terran ships to leave the planet, it made matters far worse for invaders, who would not have been able to accurately scan for the mines at the high speeds their Bartleby Drives were propelling them at.
After the Cracking of Earth, the zone became a greater focus for military operations. All of the surviving refugees (and there were not many) escaped the ruins of Earth in a convoy of transport ships crossing the Grey Zone for Proxima Centuri, which they had been terraforming for centuries in case of just such an eventuality. During that flight, however, the Terran fleet found themselves in a pitched battle trying to secure the zone for the refugees to pass through unmolested. They managed to hold of sustained attacks from both the Jatok and the East Rim forces, both of whom committed a significant portion of their forces the eradicating the Terran Menace once and for all. While some Terran losses were incurred, the majority of the refugees reached Proxima unharmed, and the Terran fleet were able to go on the offensive - leading to the Battle of [Rutt 5]?, one of the last and most decisive battles of the conflict.