What does Islam say about enemies?

As'salamualaikum Wa Rahmatullahi Wa Barakatuhu,

Your question is n't clear. But as per to my understanding enemies apart from satan who is called as an open-enemy too, there are few more enemies which lie within us. Like Pride , Envy, Covetousness, lust , Wrath --etc. If  these enemies overcome us then we are the loosers. U must be knowing that islam means submission of our will to Allah ta'ala and when we bow down to these enemies then it means we are n't submitting our will to Allah ta'ala.

  We should state here that the believers, whom the human enemies kill, become martyrs, while those who fall victim to the inner enemy - Satan - become bandits. Further, the believers who are defeated by the APPARENT ENEMY - DISBELIEVER gain a reward, while those defeated by the inner enemy earn a sin and become misguided. Since Satan sees man where man cannot see him, it is befitting that the believers seek refuge from Satan with Whom Satan cannot see. The Isti`adhah is a form of drawing closer to Allah and seeking refuge with Him from the evil of every evil creature.

Imam Ahmad recorded that Anas said that, the Prophet's front tooth was broken during the battle of Uhud and he also sustained injuries on his forehead until blood dripped on his face. The Prophet said,

How can a people achieve success after having done this to their Prophet who is calling them to their Lord, the Exalted and Most Honored) Allah revealed,

Not for you is the decision; whether He turns in mercy to (pardons) them or punishes them; verily, they are the wrongdoers.) Muslim also collected this Hadith.
There is no disagreement that it is lawful to curse the disbelievers. `Umar bin Al-Khattab and the Imams after him used to curse the disbelievers in their Qunut (a type of supplication) during the prayer and otherwise. As for cursing a specific disbeliever, some scholars stated that it is not allowed to curse him, because we do not know how Allah will make his end. Others said that it is allowed to curse individual disbelievers. For proof, they mention the story about the man who was brought to be punished repeatedly for drinking (alcohol), a man said, "May Allah curse him! He is being brought repeatedly (to be flogged for drinking).'' Allah's Messenger said:

(Do not curse him, for he loves Allah and His Messenger).

On the Whole as the above member says, we can only pray for Allah ta'ala to guide them from their strayed path.

May Allah ta'ala guide all of us to the righteous path. Ameen.