The point of my original reply concerning pre-emptive strikes was to assist me in a theoretical argument with Libertarian Party members. When the idea of a pre-emptive strike is introduced it leaves areas of gray; most Libertarians like everything in black and white. Those that adhere to a basic libertarian ideology are generally open to pre-emptive strikes but Libertarians that have taken the party pledge generally reject the idea. Maybe the only way to deal with Libertarians is to get them out of a theoretical world and into a real world, where decisions are not as simple and clear as the difference between black and white.
Why? That would be a cost and benefit analysis, not rights analysis. Besides my actions of shooting the wolf would be rightful or unrightful regardless of whether I have to buy a rifle. The proper rights analysis is to compare the costs of the two violations of rights. The wolf owner violates my rights at the price of the fence. I violate his rights at the price of the wolf. Of course, there are intangibles that I purposely excluded, reducing pet ownership to mere money, etc.
Libertarianism is a theory more than it is a casuistry. In theory we deal with hundred dollar wolves. In casuistry we deal with the recent helicopter attack on Arafat's headquarters. One can't understand the latter without the former.