1 Kings 15:17 shows us that Baasha followed something of the same tactics as his predecessor, Jeroboam. Whereas Jeroboam built the altar at Bethel to prevent the people of Israel from going to the temple in Jerusalem, Baasha was turning a city near his southern border to serve as a fortress to discourage any of his people from going to Judah for any reason. It was also designed to prevent the incursion of the forces of Judah from attacking him at that place.
17 Baasha king of Israel went up against Judah and built Ramah, that he might permit no one to go out or come in to Asa king of Judah.