The Day Of The Lord and Babylon
The oracle concerning Babylon...
(therefore, Babylon must Rise Again)
"...if the future world empire were to have [literal] Babylon as its capital, its destruction prior to the second coming of Christ would then provide a literal fulfillment of the many prophecies in the Old and New Testament relative to the destruction of Babylon."
John F. Walvoord, Major Bible Prophecies, 1991, Zondervan publishing House, Grand Rapids, MI, p.326.
Isaiah 13:17 is more likely a reference to the "spirit of the Medes" rather than the Medes themselves, per Jer. 51:11 which is set in the same context. Either way, whether a double-reference prophecy, or the "spirit of the Medes", Babylon's FINAL FALL will occur in the Day of the Lord at the End of the Great Tribulation.