I am personally not so concerned with "making friends" with my enemy as much as I am establishing a relationship built on respect and understanding. That may be that he understands that continuing to sturggle will do him no good. Or it could be the understanding that I do not plan on doing him harm past the point that he is willing to engage.
Friendship is based on trust, I find it impossible to trust someone who has tried to harm me.
A relationship based on understanding and respect for what you can do to the person who has tried to harm you is my experience.