What does 2 Chronicles 16:1 mean?

In the thirty-sixth year of Asa’s reign, King Baasha of Israel invaded Judah and started building up Ramah to block anyone from leaving or entering Asa’s territory. 2 Chronicles 16:1 - Modern Text Bible

(After decades of peace, Judah faced a new threat from Israel, as Baasha tried to cut off Asa’s kingdom by fortifying a key city.)