Moroni saw two things as important in Helaman’s letter. The first was that they had been able to remove the Lamanites from the western and southern lands. The second was that there was some problem with the government that prevented needed reinforcements to be sent. Based on those two important aspects of Helaman’s letter, Moroni does two things.
The first is that he sends a letter to Pahoran, the Chief Judge, and therefore the head of the government, pleading that he send the needed reinforcements to Helaman.
The second was that he began to map out his own plan to remove the Lamanites from the eastern borders of the Nephite lands.