After retreating to Gideon, Pahoran has called his people to arms—not to fight against the Lamanites but to fight against the Nephite rebels in Zarahemla. Since this new army centers on Pahoran in Gideon, they are not available on either the western/southern or eastern/northern fronts to bolster Helaman or Moroni. Pahoran sketches this military situation for Moroni, letting him know that it is, for the moment, stable. He has created a stalemate between the conflicting parties in the Nephite heartland.
While Moroni must have been heartened to hear of Pahoran’s loyalty, he would immediately have grasped the military nightmare: a war on two fronts against the enemy and now a civil war at home.