You're only demonstrating that you don't understand libertarianism. You don't need 100% agreement on a single issue much less all of the issues for it to be implemented.
That's because you're a raging hypocrite, something we established and moved past over twenty pages ago.
Yet a further demonstration of your ignorance. Self-defense is not aggression therefore it can't be a violation of the non-aggression principle.
Didn't you say that you don't believe we are allowed to defend ourselves against someone with a nuke? Or are we now allowed to intervene before they detonate it?
Let's look at it from a smaller scale. If your neighbor packs heat, whether or not you are aware of it, it should not be a threat to yourself; until the day comes that he either actually threatens you, or he pulls out his weapon in your presence with the pretense of pointing it at you. If he has ever threatened you before buying a gun, it would be reasonable for you to appeal to your neighbors (or elected reps, or local sherriff, whatever) that his aquiring a gun, in light of his prior inclinations towards violence, constitutes a threat upon yourself. The same can be said for nukes or the materials and expertise to produce them at the nation-state level. I'm not making up anything novel here, this is the way it actually is presently. The only difference in how a lib looks at the situation is that there is no inherent difference between an individual and a group of people large enough to be considered an independent and soverign nation. Groups don't have rights that individuals do not have.