Babylon will be destroyed because it drove the people of Judah from their homeland. The Jews will return to their homeland and this is in line with the promises of the covenant Yahweh made with Abraham to curse those who curse Abraham's descendants. The fulfillment of this prophecy would have been unthinkable because Babylon controlled almost the entire Near East. The ULB sets poetry (51:1-64) farther to the right than the rest of the text to show that it is poetry.