The fall of Babylon motif is signaled by Revelation 16:12 and 17:1, as noted earlier. The mention of the Euphrates River (Rev 16:12) and the “many waters” (Rev 17:1) are clear allusions to ancient Babylon and its fall to the armies of Cyrus, King of Persia. To understand this relationship, it is helpful to visit the fall of Babylon texts in Jeremiah and Isaiah. A good beginning point is Jeremiah 50:33-34 (NIV): “This is what the LORD Almighty says: ‘The people of Israel are oppressed, and the people of Judah as well. All their captors hold them fast, refusing to let them go. Yet their Redeemer is strong; the LORD Almighty is his name. He will vigorously defend their cause so that he may bring rest to their land, but unrest to those who live in Babylon.’” This text makes it clear that Babylon’s fall was not an accident. It was part of the direct purpose of God on account of Babylon’s oppression of God’s people.

God continues His indictment of the Babylonians in Jeremiah 50:35-36: “’A sword against the Babylonians!’ declares the LORD—‘against those who live in Babylon and against her officials and wise men! A sword against her false prophets! They will become fools. A sword against her warriors! They will be filled with terror.’” Yahweh’s attack against the Babylonians specifically targets Babylon’s officials, her wise men, her false prophets and her warriors. This is a listing of the people who made Babylon strong; her administrators, her thinkers, her religious leaders and her military personnel.

The prophecy continues in verse 37: “A sword against her horses and chariots and all the foreigners in her ranks! They will become women. A sword against her treasures! They will be plundered.” The previous verses talk about officials, wise men and warriors. Now this verse talks about horses and chariots, mercenary troops and treasures. Again this is a listing of the resources that make Babylon strong! But there is one more resource that has not yet been listed (Jer 50:38 [NIV]): “A drought on her waters! They will dry up. For it is a land of idols, idols that will go mad with terror.” What are the waters being dried up here? The waters of Babylon, the Euphrates River!
You see, the Euphrates River was part of the defenses of ancient Babylon. It provided a moat around the city that made an attack against the walls almost impossible to carry out. But the Euphrates River was even more than this in Jer 50:38. It had become a symbol of all the resources that supported ancient Babylon, including the warriors and officials and treasures that made Babylon strong. When Revelation 17:15 interprets the Euphrates River as a symbol of the civil and secular powers of this world in support of end-time Babylon, it is using the Euphrates River in a way consistent with its usage in the Old Testament. The drying up of the Euphrates symbolizes the loss of Babylon’s strength to defend herself. This theme is repeated in Jeremiah 51:36-37 and Isaiah 44:24-28, with the inclusion of Cyrus as a key player in the drama of drying up the Euphrates (Isa 45:1-4).

With this in mind, let’s summarize the fall of Babylon, as narrated in the Old Testament, in a sequence of five events. Cyrus, king of Persia (a “king from the east”—Rev 16:12), dried up the literal Euphrates River, conquered the city of Babylon, permitted Israel to go free, and arranged for the rebuilding of Jerusalem. This five-part narrative clearly sets the foundation for the last portion of the Book of Revelation (chapter 15-22). In the Book of Revelation an end-time Cyrus (the “kings from the rising of the sun”—Rev 16:12), dries up the end-time Euphrates River (Rev 16:12, cf. 17:15), delivers end-time Israel (Rev 18:20 – 19:1-5), leading to a New Jerusalem (Revelation 21-22). In other words, the fundamental narrative substructure of the Revelation 16-22 is grounded in the Old Testament story of Cyrus and Babylon’s fall. The conquest of Cyrus is, so to speak, a subtext for everything that happens in Revelation 16-22.