What are the real threats? I agree with the isolationist libertarians that many (if not most) of the security measures imposed by the current government are hostile to our self order society. But I think they are making errors in several key respects.
First, the measures of themselves are not particularly onerous, especially because we are in a quasi-war situtation. What concerns me is primarily is that the domestic security apparatus is asking for additional powers when existing ones have not yet been tried and found wanting. It is the natural pattern of a bureaocracy to attempt to solve previous failures with an expanded budget / powers / mission. In this sense I object to these security measures not so much because of their infringement per se, but because they are ineffective infringements. On the other hand, many libertarians seem to view this as some kind of vast and intricate fascist plot, which is not a helpful analysis of the situation.
If the first mistake is taking the domestic front too seriously, the other is not taking the foreign one seriously enough. As current and proposed domestic security measures can only be part of a totalitarian plot, foreign countries (such as Iraq) can only be a threat if they're gearing up for a full scale amphibious invasion of the continental US. Apparently not even unprovoked attacks on our allies counts as a threat. For me, the best way to discredit the domestic security issues is to finish off the external enemies. This is a big difference because for many isolationist libertarians our current military operations are an excuse, not a solution. I think that is a big mistake, a mistake in the vein of the socialist / pomo school where there wouldn't be any conflict if everyone would just play nice (shades of Orrin Judd's utopian fallacy!).
The final mistake of the isolationist liberatarians is that, even if their analysis is correct, we're still deep in a hole and deciding to stop digging is helpful but not really a solution. We as a nation have duties and obligations. While I favor a more isolationist foreign policy long term, that's not currently a viable option. If there's a mess in the neighborhood, sometimes you just have to clean it up even if you weren't the major contributor. Welcome to reality.