Gotta love Marine fighting doctrine.
A friend? Really? Family I can see, especially the children. But, a friend? Why should your children (hypothetical) be deprived of daddy, so that your friend's children could have theirs?
I dont have any kids, I love my friends like brothers and sisters and I wouldnt hesitate to take a bullet or jump on a grenade for them, my close friends that is
When you get older - this will change. Like I said - Depends.
Live to fight another day! Avenge your friend's death, instead of letting him avenge yours!