Arch-enemies are two individuals or groups that are deeply hostile or opposed to each other. Antonyms for arch-enemies include allies, friends, supporters, comrades, partners, associates, and confederates. These words suggest a positive relationship and cooperation between two parties, rather than the negative and confrontational nature of arch-enemies. In many situations, finding common ground and working together can be more effective than fighting against each other. Hence, instead of having arch-enemies, individuals and groups should strive to create ties and build alliances with each other to promote peace and harmony.