What will God do to the Euphrates River so the 200 million man army can cross?
God will dry up the Euphrates River, leaving it dry as a bone. This removes the natural barrier, so the 200 million-man army will not need bridges but will simply migrate across it. The existing bridges across the Euphrates could not accommodate such a vast force.
Les explains that at this point there is still one great natural barrier, the River Euphrates. The bridges across it today could not handle moving 200,000,000 men. So in a future chapter, God will dry up the Euphrates, making it dry as a bone, and the army will simply migrate across without bridges. This fits the period when God is doing the supernatural and sovereignly causes the Chinese authorities to send that army westward.