This article has a real world counterpart outside of Left Behind.
This subject has a counterpart in the real world. However, information in this article comes from the fictional universe of the Left Behind franchise.
The Euphrates River is one of the major rivers that run through Iraq. In the Left Behind books, there were four angels bound in the Euphrates that were let loose upon the sixth Trumpet Judgment to slay a third of the world's remaining population (primarily nonbelievers) through the 200 million horsemen that appeared in "Assassins". The Euphrates was also dried up at the sixth Bowl Judgment in "Armageddon" in order to prepare the way for "the kings of the east" to gather their armies together with those of the rest of the world at the Valley of Megiddo for the great battle against God and Jesus Christ.