After the enemy launched an attack, our army quickly organized effective counterattacks.

counterattacks 是名词 counterattack 的复数形式。counterattack 由前缀 counter-（表示"反对、对抗"）和 attack（攻击）组成，字面意思是"对抗性攻击"，即"反击"。 counterattacks 指军队或团体为应对敌方进攻而采取的主动回击行动。