There were three Babylonian invasions of Judah.
In 605 B.C., Babylon went to war with Egypt and God’s people were caught in the middle. Judah had sided with Egypt, and for that transgression, the King of Babylon defeated Judah as well, taking some of her princes as hostage back to Babylon. It wasn’t just unfortunate happenstance. God had planned it. Among the hostages was Daniel, who wrote the book which bears his name. He wrote in Babylon, and his book is a reminder of how God rules over the nations of men and can bless His people no matter where they live.
In 597 B.C., Babylon once again went to war with Egypt, and once again, Judah sided with Egypt. This time, in defeating Egypt and Judah, the king of Babylon took hostage the King of Judah (Jehoiachin), replaced him Zedekiah, and took more hostages. Those in captivity did not believe they would stay long. They earnestly believed they would be delivered, and the source of deliverance would be their kinsmen back home in Jerusalem. The captives believed their sins had separated them from God and His people and the Promised Land. Those left behind in Jerusalem must be the truly righteous, they thought, because they were not in captivity! In time, they would come rescue their brethren.
Five years after the second captivity (and six years before the third). Ezekiel began his ministry. He offers his listeners/readers in Babylon insight into what was truly going on in Jerusalem. If they were expecting deliverance from that quarter, they will be disappointed. The sins of Jerusalem’s inhabitants are every bit as bad, and more so, than any they have committed. There will be no deliverance by them.