Whithersoever they went out, the hand of the Lord was against them for evil, as the Lord had said, and as the Lord had sworn unto them: and they were greatly distressed. (Judges 2:15)
That is, whenever they went out to fight or embarked upon a military campaign, they were beaten because God was no longer with them. Victories might have been interpreted as the sanction of God upon their sinful course and would thus have served only to confirm and to harden the Israelites in their apostasy. This was one of the reasons why God allowed the heathen peoples to win and thus to punish His disobedient people. Yet in all this the purposes of God were salutary. His punishments were corrective, designed to lead the Israelites back to their God.