 Once the rivalry had begun, the external threat (Assyria) provided compelling reasons for a détente.Any rivalry between Menahem and Pekah could only appear more and more foolish in light of the growing menace of Assyria.In 733, Tiglath-Pileser campaigned against Damascus, the capital of the Arameans, Pekah's erstwhile ally, and he returned to destroy the city in 732.