The fate of the kingdom of Judah was sealed long before its final days. During the reign of Manasseh, a severe decree was issued determining that Jerusalem and its Temple would ultimately be destroyed [שטיינזלץ].
God declares that He will cast away Judah, just as He previously removed the kingdom of Israel. This divine abandonment will take the form of God completely rejecting both the city of Jerusalem and the Temple. The loss is absolute, standing in direct contrast to His earlier promise that His name would reside in that very place.