Well, if I have a gun drawn and aimed at your head, you certainly can't win any fight with me, either. The problem lies not in the fact that you have a device which prevents me from winning any fight with you, but in the fact that the device also threatens everyone within range. A bomb is not a shield.
Assuming that the mugger was using a nuclear hand grenade, yes. But he's not. He's using a firearm. Use proportional force, ie another firearm. You're not just carrying a big gun. You're pointing that gun at everyone in range, and saying, "Better not fuck with me, or I'll blow you all away!"
It's public property. That's where the problem lies. It's his land too. Get your friends out of his shooting range, if you feel they're being threatened.
Again, a loaded gun is fine, as long as it's not being pointed randomly at people. A nuclear device is fine, as long as it's not armed. Armed is not loaded. Armed is hammer cocked and pointed.
A tool is a tool. A nuclear bomb is a tool to make a very large explosion. That explosion can be used for good (say, asteroid mining) or evil (blowing up a city). Guess which category your retributive vest falls under.
1) Assuming you get your gun out. I've taken out the uncertainty. You
will lose a fight with me. We both will. You can never win. A threat is not harm. Where's the harm? Threat is also highly subjective.
Indeed, you have removed the uncertainty. You've drawn your gun, and pointed it at the skull of everyone in range of the explosion, simply by being there with an armed nuclear device. I'm sure you can see how that will lose you friends. And while a threat is not harm, it is aggression. You do not have the right to initiate the use of force, the threat of force, or fraud against another person. This is known as the Non-aggression principle, and it is the guiding concept of libertarianism.
2) Why proportional force? Where's the rule saying that? You you wish to give the robber a possibility of success? Read Sun-Tsu, he's not a proponent of proportional force either. Yes, there's a risk of collateral damage. Not my problem.
But it is your problem, because it's not collateral damage. it's the bomb doing it's job. You nuke a city because a mugger shot you, it's not his fault that you killed everyone else in range.
3) We're back to intended use then. Something you were a proponent of earlier iirc. And for the question you ignored. My family IS leaving, it's just that they're not out yet. And he's going to shoot NOW. So, what are my options? He will not listen to my plea.
Stay off public land, then, and stay in privately owned parks, where the owners are intent upon it remaining a park, and not being used as a shooting range. Public property is public property. You cannot stop someone from using their property in whatever manner they desire.
4) Where's the harm? And that's your opinion. I don't see it like that. Who's correct? Who gets to decide?
Again, you're threatening the use of physical force upon completely innocent strangers. That is the harm.
5) Thanks Cpt Obvious. I think we all know what a nuke does. Everyone should be allowed to wield that much destructive power in case they want to take up asteroid mining?
Yup.