Love your enemy. But don't forget, he is not your friend.I find this in the truest sense of the word. We sometimes are cornered by the social dictates that you should treat people well even if they have hurt your or even if they are your enemies.
It is fine that one person tries hard to love someone who has put a dagger behind your back. Let the past leave behind. But we should always be wary of the history that this person has inflicted on you. You still have to be cautious.