Rehoboam ¹  and Jeroboam were continually at war with each other throughout Abijah’s ²  lifetime.

(5:1) ¹  Solomon ruled all the kingdoms from the Euphrates River ²  to the land of the Philistines, as far as the border of Egypt. These kingdoms paid tribute as Solomon’s subjects throughout his lifetime. ³ 

I will not take the whole kingdom from his hand. I will allow him to be ruler for the rest of his life for the sake of my chosen servant David who kept my commandments and rules.

He did this ¹  because David had done what he approved ²  and had not disregarded any of his commandments ³  his entire lifetime, except for the incident involving Uriah the Hittite.