Allan Walstad wrote, "It would be nice to see such issues argued on their merits without some libertarians seeking to pin a scarlet "deviations" tag on their fellow travelers."
To which Roderick Long responded, "Hey, I'm the moderate here! Other people have been arguing that those who endorse serious deviations from libertarian purity no longer count as libertarians at all, and I've been arguing against that view.
"If you don't like 'deviation,' what term would you prefer as shorthand for 'view put forward as libertarian but actually (in the opinion of the speaker) inconsistent with libertarian principle'? (Because we need such a term, I think.)"
I agree, and I want to take this opportunity to clarify something: When I say someone can't be a prowar anarchist or libertarian, I am not saying that person cannot have a basically libertarian philosophy overall, or that that person has nothing to teach or offer (of course, that would be absurd – without learning from statists, we could learn practically nothing!), or that there isn't some sense in which it's useful to call such people libertarians or even anarchists. I consider them in error, to the point that calling someone a "pro-war libertarian" strikes me as oxymoronic, and yet I see some use in the label. But I do think it is a deviation.
What I don't agree with is the idea that there is something special about foreign policy that makes it more okay for so-called libertarians (or libertarians very broadly defined) to radically disagree on it than on other issues. In the sense that someone can be a pro-war libertarian, I think one can also be a pro-gun control libertarian, a pro-income tax libertarian, a pro-conscription libertarian or a libertarian thief. But all these are contradictory, and I tell those who I believe are making a bad error on war that, insofar as they make that error, they are clearly straying from libertarianism, because my purpose is to explain why, in my opinion, libertarianism, if it to be taken seriously as a political philosophy, must preclude government war, especially of the modern kind that has been typical of the last century and which the US has pretty much exclusively practiced.
Thus, I think there is some value in calling people libertarians, despite deviations on pretty much any issue, including taxation, gun restrictions, immigration controls or socialized medicine. (Most libertarians would draw the line here, but for one purpose of description, I would not.) But I also think there is another sense in which libertarianism precludes all this, as well as any and all advocacy for state power and activity. (Indeed, if there's any deviation that would disqualify someone from being a libertarian, I would say it's support for war, which is a greater violation of libertarian principle than nearly anything else government does – but I am willing to be big-tent about it to some degree. If you supported the invasion of Afhganistan or even were originally for the Iraq war, maybe you're a libertarian nevertheless. But if you are, then so is anyone who is generally pro-freedom to a sufficient extent, despite some serious deviations. Many people, however, who are very pro-war take it to a level that I find the description of them as libertarians to be totally unjustified.)

