Against whom were the Israelites fighting when King David committed adultery with Uriah's wife?

King David committed adultery with Bathsheba, the wife of Uriah the Hittite, while he was at war. The war was being fought against the Ammonites, who had attacked the Israelites and had taken control of some of their cities. David had sent Uriah to the front lines of the battle, hoping that he would be killed in battle so that he could marry Bathsheba. However, when Uriah did not die in battle, David arranged for his death by ordering his generals to withdraw from him during the fight, leaving him exposed to the enemy. After Uriah was killed, David took Bathsheba as his wife and committed adultery. Therefore, the answer to the question is that the Israelites were fighting against the Ammonites when King David committed adultery with Uriah's wife, Bathsheba.