v1-5: Tola and Jair led Israel for 23 and 22 years respectively. Tola lived in central Israel, Jair in Gilead, east of the Jordan.
v6: The next cycle began, with sin and idolatry. This seems to be more serious as the gods of seven nations are mentioned. It is suggested that the pragmatism of ch 3-9 gave way to hedonism, as the people pursued pleasure for its own sake.
v7-9: The oppression and suffering were apparently worse than previously. The area ruled by Tola was attacked by Ammonites, and there was deliverance by Jephthah; the area ruled by Jair was attacked by the Philistines, and there was deliverance by Samson. This confirms the suggestion that the Judges ruled, and the oppression occurred in regions within Israel, and not necessarily throughout Israel.
It may be said that the lack of obedience of the tribes east of the Jordan had turned to open idolatry, see Num 32.1-5.
The Ammonites were a Semitic, not a Canaanite people; mentioned in Num 21, and Deut 23.3-6.
v10: Israel prayed to the Lord, although it may have been because of their suffering, rather than true sorrow for their sins. This was apparently a last resort after 18 years of oppression. See also v15. The actual area attacked was significant, with both Ammonites and Philistines involved.
v11-14: 'Do you really mean it?' is the Lord's response. The people were so quick to turn to foreign gods, but so slow to return to the true God. Why should He listen to them?
v15-16: In response the Israelites removed their idols, and served God. This was a sign of real repentance, which God honoured.
v17-18: Having dealt with matters of repentance and obedience, Israel still had the practical problem of a foreign army in their land. The leaders met together, to find a suitable military leader. They managed to gather something of an army.