It's admirable that your son doesn't want to fight, and he needs and deserves your support. Talk with him and let him know that you are proud of him for not fighting and that you will support him in this. Let your husband know the same thing.
Most parents don't really want their children to hurt someone else; they actually want their children to learn to stand up for themselves. Talk with your son's school counselor about helping him learn some positive assertiveness and problem-solving skills.
Since this is an issue, you may also want to think about helping your son find some new friends. Joining a soccer team, Boy Scout troop, or church group may help him make some friends who feel the same way he does about fighting.