Albert Barnes Commentary 2 Chronicles 19:1

"And Jehoshaphat the king of Judah returned to his house in peace to Jerusalem." — 2 Chronicles 19:1 (ASV)

Jehoshaphat ... returned to his house in peace - With the battle of Ramoth-gilead and the death of Ahab, the war came to an end. Because the combined attack of the two kings failed, their troops were withdrawn, and the enterprise they had undertaken was relinquished. The Syrians, satisfied with their victory, did not press the retreating enemy or carry the war into their enemies’ country.