Final answer:
The cycles in the book of Judges depict a downward spiral of Israelite society, but Jephthah's marital alliances are not a subject of these stories.
Step-by-step explanation:
The statement in the question is partially true. While it is accurate that each cycle in the book of Judges portrays a downward spiral of Israelite society, characterized by a pattern of sin, oppression, repentance, and deliverance, the specific detail regarding Jephthah's involvement with foreign women is not found in the biblical text. The book of Judges does include narratives where leaders engage in questionable behavior, such as Jephthah's rash vow in Judges 11, which leads to the sacrifice of his daughter, but it does not mention him having an immoral relationship with foreign women.