What does the drying up of the Euphrates River do for the 200-million-man army in Revelation 16?
The drying up of the Euphrates removes the last natural barrier so the 200-million-man army from the east can come. It prepares the way of the kings of the east, allowing those nations to move toward the Middle East and Jerusalem.
Les explains that the sixth angel pours out his bowl upon the great river Euphrates, and its water is dried up. The stated purpose is 'that the way of the kings of the east might be prepared.' Les had previously taught that the Euphrates is the biggest natural barrier to the great army coming from the east. With the river dried up—even as the Turks' dam on the headwaters could help dry it downstream—the rivers will be such that the nations of the east can come. He sees this as the last obstacle being removed for their 200-million-man army. Then the satanic powers go out to the heads of the nations of the world to send their armies to the Middle East, to Jerusalem in particular, setting up the battle of Armageddon.