Ai plays a major role in Joshua 7-8 because Israel's experiences there demonstrate both the seriousness of covenant disobedience and the restoration that followed judgment. After Jericho, Israel expected Ai to be an easy victory. Instead, the Israelite force was defeated and approximately thirty-six men were killed.
The narrative explains the defeat through Achan's disobedience. After the matter was exposed and judged, God again commanded Joshua to attack Ai. Joshua 8 describes an ambush that resulted in the capture of the city.
Ai therefore serves in the biblical narrative as more than a military objective. The contrasting defeats and victories emphasize Israel's dependence upon God and the consequences of disregarding His commands.