CShirk, you make some useful points but you’ve sort of twisted away from my questions. I am not so much interested in states and state-like groups, but rather in the risk that a homicidal individual (or small group of psychopaths) can pose to large groups of “innocent” people, and whether individuals through the state or through their own initiative are justified in taking aggressive action to prevent other people from acquiring the means to commit an asymmetric act.
Perhaps I should define “asymmetric act:” This would be an act of violence that cannot be anticipated and whose damage is totally out of proportion of the ability of people to defend or retaliate against. We could argue that a democratic state with a truck bomb is not an asymmetric threat. If they drive it into our town and kill hundreds of us, we can retaliate. There is also the potential to anticipate a state’s action – we can maintain intelligence activities against them, diplomatic relations, borders, etc. But an individual with a truck bomb is asymmetric: Your next door neighbor could build and detonate one, and not only may you never realize he was disposed to such an act, but he could even commit it and conceivably get away with it. And even if he were connected to the crime how can you hold one man to account for the wanton murder of hundreds? There is no way to deter, defend against, punish, or seek redress for an average guy who snaps and has ready means to commit a truck bombing.
Contrast this with firearms: Yes, psychopaths arm themselves and launch shooting sprees. But individuals who care can deter and defend against such acts by arming themselves with guns, and in the worst case a gunman kills a few people before being stopped, which is not out of proportion to the punishment that can be meted out to him.
BTW, your description of detonators is not accurate: Explosive devices can be made from gunpowder, but detonators capable of triggering a true “high explosive” are difficult and risky to make at home. Just look at the number of random acts of violence committed domestically with low explosives versus the number committed with high explosives: Of the many domestic crimes committed with explosives exactly one has succeeded in mass detonation of a high explosive. In any case, we need not dwell on these nuances because I have also offered nuclear weapons as an example: Not only have our bans on possession and trafficking in refined weapons-grade material been completely effective (domestically), but it seems extremely unlikely that a black market or domestic hobbyist will ever succeed in violating it. However, without such a ban we know that it would be fairly easy for an individual to build and use a nuclear bomb.
Note also that this is the empirical rebuttal to those who think bans can’t work: We have plenty of evidence of psychopaths who have set out to commit mass murder with the most powerful weapons they could acquire. Yet the total number of realized acts involving high explosives: 1; involving nuclear explosives: 0.
Now again to the question: Have these bans cost us more than they have benefited us? Just imagine if every shooting spree or bombing was instead a nuclear explosion. That’s a pretty high hurdle you have to overcome! And even if our state in actuality has abused our liberty to protect us against these threats, can you argue that in principle it is unjustifiable for a state to preemptively ban these items? What about individuals: Is it legitimate or not for them to initiate aggression to enforce their own ban against these items? And where and on what basis do we draw the lines on who may use aggression, against whom, under what conditions, and against what contraband?