Revelation 18:2

The repetition of the word "Fallen" (cf. Revelation 14:8; Isaiah 21:9; Jeremiah 51:8) probably indicates that God guaranteed this judgment and that it will happen quickly (Genesis 41:32; cf. 2 Peter 3:8). This is another proleptic announcement in which the angel described a future action as already having happened. The prophetic aorist tense of the Greek verb makes this clear.

"It is the prophetic way of declaring that the great purpose of God in triumphing over evil is a fait accompli." [Note: Mounce, p. 323.]

The description of Babylon in this verse is what it will be after God judges it (cf. Isaiah 13:21; Isaiah 34:11; Isaiah 34:14; Isaiah 47:7-9; Jeremiah 50-51; Ezekiel 26-28; Nahum 3; Zephaniah 2:15). Ancient Babylon fell to Cyrus the Persian in 539 B.C., but that fall did not fulfill Old Testament prophecies about Babylon completely (cf. Isaiah 47:11; Jeremiah 51:8). [Note: Kiddle, pp. 359-60; Wilcock, p. 168; Bullinger, p. 553.] John had described God only through hymns of worship to this point, and he now similarly described the fall of Babylon through the laments of onlookers. [Note: Caird, p. 227; Sweet, p. 267; Mounce, p. 323.]

"The prophecy thus indicates that before the advent of the warrior-king in Revelation 19:11-16, Babylon will rise to its greatest heights, not only of idolatry (chap. 17), but also of luxury (chap. 18). . . . Babylon of the future, therefore, will be the center for both false religion and world economic prosperity." [Note: Thomas, Revelation 8-22, p. 317.]

Apparently it is the city that will be the prison of demons, a place where they are safe but kept against their wills (cf. Isaiah 13:21-22; Isaiah 34:11-17; Jeremiah 51:37). A prison (or haunt) for unclean birds is a figure of desolation (cf. Isaiah 34:11; Isaiah 34:13; Jeremiah 50:39). Babylon will become utterly desolate.