Anthony, what struck me about that passage is the sheer hackery it evinces. The "blame-America" nonsense is typical of mainstream political idiocy, and yet a libertarian -- you know, someone who's supposed to be a little skeptical of dumb-guy political slogans -- is going to repeat it with a straight face? Who are these people?
Why does "serious political engagement" have to involve going along with the establishment on war? You're not really being "serious," I guess, unless you're looking for a country to bomb, or unless you're repeating propaganda that the rest of the world cannot believe some of our people are still simple enough to buy into -- six freaking years after 9/11. And both parties already favor interventionism abroad. Why would it be such an unspeakable tragedy if pro-war "libertarians" stayed out of "serious political engagement"? Who needs them anyway? Is the establishment not sufficiently pro-war for this guy as it is?
Oh, and why is it assumed that "young people with classical liberal instincts" will be turned off by an antiwar posture in the first place, or will find it odd or surprising? Has the guy never heard of Richard Cobden? (Nevermind; I know the answer.)