Upon his return to the Land of Israel, David promotes Amasa, the rebellious Avshalom’s chief of staff, as his own chief of staff, replacing Yoav (Joab.)  He pardons Shimei son of Gera, who had verbally abused him as he fled Jerusalem, and pardons Mephiboshet, who had also been accused of treason, and restores half his estate.  This is much like his generous treatment of the survivors Shaul’s regime.  Making war against David is much like making war against the United States.  Losing is the best thing that could ever happen to you.