h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Riding home today with an older friend who has two sons, I witnessed some of his disciplining tactics. One boy was annoying the other by singing a song he particularly dislikes (because it has his name in it), and so the annoyed hit the annoyer. Repeatedly. And hard, too; the kid takes karate lessons.
So the annoyer hit back, of course. This cycle, with interjected comments from thier father, went on for a good 15 minutes. They were choking each other, and their father is laughing? I suppose his reasoning is if he doesn't treat it serioulsy, the boys won't either and it won't be a big deal. Besides, they are boys; the father is an ex-army Captain and his sons need to know how to fight to survive in this tough world.
Finally, the father had enough, and made the annoyer stop and be quiet by pulling on his son's arm (while driving, of course).
I didn't say anything, but wonder now: what are the children learning? If their father does't come down hard on them for being violent (and they really were; those kids can throw some punches), won't they tend towards that whenever they get angry? When disciplining a child because of his violent behavior, is it wise to inflict violence as a punishment? Surley it only shows him that violence is an effective means to an end.
Even Our Friend and Great Counselor Mr. Machievelli says that ruling by fear alone is not the best method (which is apperently what this fellow is doing), and even he should be somewhat disregarded as an authority for child-raising, since one's offspring do not usually revolt at 5 or 6, or even 9 or 10. Pretty much after 12 you can't do much with them if they haven't already learned.
It just bothered me that he wasn't teaching them that fighting was wrong. Maybe I am an idealist...but I don't think the world needs anymore fighters. Thinkers, yes. Fighters, no.