Many warriors would descend on Israel like the waves of the sea, but they would quickly dissipate because the Lord would rebuke them. They would disappear like dust before a strong wind. The terror that would be so strong would vanish overnight. God also gave such a deliverance to Judah when Sennacherib the Assyrian attacked Jerusalem (cf. Isaiah 37:36), but that is not in view here. The fact that Isaiah did not mention a particular nation as the enemy, suggests that he had more in mind than just one foe, and a perspective that extended far beyond his own day. Many nations would punish Israel over the years. [source][source][source]
What follows in chapter18 is an example of how the nations are subject to God, the point of Isaiah 17:12-14. It describes an eschatological defeat of superpowers-one of which would destroy Damascus and Ephraim in Isaiah"s day. [source][source][source]