As I read through the book of Judges, there are moments when I wonder why all of this is in the Bible. It is rapid-fire storytelling that jumps from one battle to the next. It seems to not have much to do with following God - until you catch the little lines that connect the battle scenes.
The phrase "again Israel did evil" is like a hook that latches each story together. Following deliverance there is peace. Once the leader dies, Israel abandons God. This leads to Israel being handed over to another power and the cycle starts anew.
We can choose to get lost in the battles or look more intently behind the scenes to see the real battle for the heart. As long as the human heart is not inclined to follow the Father, there is no peace. Some of us accept that on a personal level but often forget that it applies to a societal level as well. This life will never be a life of peace and rest until we decide to rest in the will of the one who designed life in the first place. As St. Augustine said in his Confessions, "Are hearts are restless until they find rest in you."