Moroni needed as much help as he could get, but his first concern was about the immediate need of Helaman and the 2,000-plus stripling warriors. They had taken all that part of the land back from the Lamanites, but did not have very much manpower to maintain it.
First, Moroni asked for help from Pahoran to strengthen Helaman and the troops that were sustaining that part of the land. However, then Moroni discovered that Helaman had done so well in defending the city of Manti, that all those Lamanite soldiers had fled from Manti to Nephihah, an area that Moroni was trying to defend. Now Moroni had double trouble. He tried to hold on, but ultimately lost the city of Nephihah. This loss caused him to worry about the wickedness of his people, and he feared that they may lose their lands to the Lamanites.
And famously, “And it came to pass that Moroni was angry with the government, because of their indifference concerning the freedom of their country” (v. 13).
Book of Mormon Central, “Why Was Moroni’s Correspondence with Pahoran Significant? (Alma 59:3),” KnoWhy 168 (August 18, 2016). “The correspondence between Moroni and Pahoran also provides important glimpses into the personalities of these men. Although a man of great faith, it is clear that Moroni was also susceptible to anger, frustration, doubt, and misplaced outrage at those whom he assumed had slighted him. At the same time Pahoran is revealed in his letter to be a man of patience in the face of being wrongfully accused.”