Alma 52–53 are a verification of the Savior’s statement that “all they that take the sword shall perish with the sword” (Matthew 26:52). Led by wicked and apostate Nephites (Ammoron and others), the Lamanites sought to violently capture and maintain Nephite cities. Each city was taken at a high price, however: “They had not taken any cities save they had lost much blood” (Alma 52:4). Captain Moroni was always reluctant to take up the sword and far more eager to lay it down for peace (see Alma 52:37). He knew that even when the Nephites were victorious, it cost thousands of lives on both sides.
War would never occur if all people were living the gospel of Jesus Christ. He is the Prince of Peace, and those who follow Him are emissaries of peace.