Simply, invasion and conquest. Search for the invasion of Judah by Babylon. Why? Because God said, "Surely at the command (mouth) of the LORD it came upon Judah, to remove them from His sight because of the sins of Manasseh, according to all that he had done, and also for the innocent blood which he shed, for he filled Jerusalem with innocent blood; AND THE LORD WOULD NOT FORGIVE.” 2 Kings 24:3-4
Manasseh was the king of Judah and set the precedence by example. He allowed it. He set the laws that were in place. The majority of the people followed suit. Do you know of any nation that practiced human sacrifice that was not invaded and still exists today?