Although military service is no longer compulsory in the United States, American males age eighteen to twenty-five have to register with the Selective Service. If you do not register, you may be denied benefits and employment opportunities. James recently turned eighteen. He is opposed to war and is considering not signing up. He is explaining this to his parents. James says, "Look, I don't want to support a system that fights unjust wars and I won't fight in one. So I'm not going to sign up." James's father is a military veteran. He responds, "We've all got a duty to serve our country, whether just or unjust. And anyway, you're wrong to claim we fight unjust wars. Our military fights justly. Do your duty and register." James's brother has a different opinion. He says, "Your moral principles don't apply in war. There are no just or unjust wars. There are only winners and losers. It's better to be on the winning side. You should register because you want the benefits and don't want to get busted."
Whom do you agree with here: James, his father, or his brother? Should a person register to fight if he doesn't believe in the justice of the wars that are being fought? How should moral principles apply in this case?