I don't jump out of a plane in the air without a parachute because I might survive without doing myself any serious damage. In the same way, I don't base rational decisions of self-defence on what a person might do afterwards. This is not realistic. To be realistic you need to pay what you owe first before you give away to random strangers. And you owe your family its protection. You don't owe an attacker anything.
I can't compare what I'm suggesting to jumping out of a plane without a parachute. It's like comparing jumping off the temple roof because of temptation to me showing mercy to my enemies or asking God to forgive them while they murdered me. Apples and oranges, imo.
As for realistic, I've had a gun to my head and seen my loved ones robbed in front of me. There was nothing I could do without getting us all shot. And we begged for our lives when they told us to start climbing the staircase to the roof. If I could go back in time to that situation and relive it, I would not want a gun. I would want what I have now, no fear of death (Heb 2:15) and the knowledge of God.
As for family, I view the attacker as God's child who is dead in sin and lost. My self-defense response will be tempered by that reality because I believe it and my choices are determined by my beliefs. Whether or not I owe my family protection in every sense is debatable. You first have to define family and explain why others are excluded, like the unborn victims of abortion.
One of the problems with non-violence is that in its origin it is just another form of legalism. The idea of turning the other cheek, loving your enemies and so on, gets converted into a new law, the law of non-violence. The law then gets its own existence independent of what gave it its birth. That's what law does.
But Jesus did say love your enemies and be merciful as God was merciful to you. In what way have I misunderstood that? I don't see that His words preclude physical force or cunning to defend oneself. However, I do see that mercy precludes killing a lost person who is already dead in sin when you have the power to let him live.
A person can still serve in the army and not be a violent person. The best people for the army are those who are not violent. Being non-violent is not the same thing as letting others be violent to you without redress. A violent person is someone who is quick to take revenge, someone who enjoys breaking things and breaking people and looks for opportunities to do so. Making a law out of non-violence destroys this distinction and can be very dangerous, allowing great evils into the world.
I don't need violence to defend myself or my family, so it's not a law for me. We believe God protects us; He shows us and provides for the reasonable precautions we need to take in this evil world.
As for the Army, I served in combat and know a little about fighting. In war, it's best to win without firing a shot while using non-lethal force and cunning.
In the United States, there is a duty to retreat from attackers. You can't just gun someone down. Castle doctrine doesn't apply in a dark alley, as far as I know.
I should also mention that it takes training to defend your family against armed attackers. Most people would be incapable of doing anything in a real situation; it's all just tough talk.
