There is a continuum of political "philosophies" that proceeds from anarchism to totalitarianism. Libertarianism happens to be one step right of anarchism (albeit a very short step), but that does not make it any more realistic as a governing philosophy. Indeed, that phrase is an oxymoron - it is not a "governing" philosophy. I note that while Issodhos, as apparently the only defender/explicator of libertarian philosophy participating (my sympathies, friend), has written much, and answered a number of comments, he has not provided much substance to respond to - or had no one actually noticed that? I don't mean to pick on you, Issodhos, just no one else taking your position.

There are no specifics, just generalized "philosophical" leanings, e.g.
police-state entities like Homeland Security and other intrusive and suppressive policing actions meant to increase control over the citizenry would cease to exist under a libertarian-influenced society because there would be no government-caused need for it
I'm sorry, security is a "government-caused need"? or
If the system of social programs and other government actions were working, there would be less of a problem now.
Nice platitudes, but really no substance. And the "intelligence agencies" that are going to cooperate, where do they come from? Indeed, I have found nothing of practical utility in any of the responses (and a great deal of avoidance and misdirection - like responding to questions with questions). I do understand why, and it goes back to Phil's original posts.

There have been a number of references to "libertarian-influenced" positions: because that is all it can be, an "influence." Like conservatism, it is not so much a political philosophy or organizing principle, but a reaction against. Mostly against government. Mostly against anything that provides for collective solutions, other than notional "voluntary" organizations (as opposed to any real-world organizations). Take for example, the problem of roads that was posited earlier, or hospitals. If we rely on people to "voluntarily" give up property, road systems would become unusable, and economically unsustainable. They would meander thither-and-yon as easements became available at the lowest cost, and the later in the process requests were made, the higher the value demanded for such easements would become until they became unavailable... and the road just stops there. Hospitals would be sited not based upon community utility, but based upon the profit incentives of particular land-owners. Prisons would find few takers at all. Fire stations might abound, but who would man them?

Issodhos has suggested that subsidies for local communities and States would be eliminated - which of course would lead to the disintegration of those communities who do not have natural economic bases from which to draw resources. There would be a race to the bottom in terms of granting of favorable terms to entice corporations to site in the community - something we have already experienced. Local businesses would be supplanted and eliminated by larger conglomerates, not because of greater efficiency or merit, but based upon size and influence. There would be no one to stop it.

The problem, in short, with the libertarian approach, and what makes it ultimately a failure as such, is that it never provides the countervailing interest, and indeed strips the means of local autonomy away entirely in the interest of economic/social "purity." I cannot identify a single area of public life where "libertarianism" would be a net positive. Taxation cannot be voluntary. Eliminate the IRS? Sure, who would collect taxes? Who would support the court system to protect those "inalienable" rights and property interests? Who would guard against corrupt practices? Who would provide police protection? How could the military be supported sufficiently to protect either local or national interests? There are no real solutions, because that is not the point of the philosophy. It is not about real-world solutions. It's all pie-in-the-sky naivete, and even less coherent than communism, which at least has a governing principle.

The only level of applicability of libertarianism is in the formation of clubs. Really, that is what it boils down to - the formation of clubs with similar interests. Beyond the few dozens, or generously, thousands of people who participate in such an organization, it has no teeth. The best exemplars I can think of are the Elks, the Rotary, and the VFW. While these may be laudable organizations, they hardly represent practical examples for governing say a million, 5 million or 300 million people - just picking the numbers out of the air as examples. That is why libertarianism quickly devolves into irrelevancy when applied to the real world.
A well reasoned argument is like a diamond: impervious to corruption and crystal clear - and infinitely rarer.

Here, as elsewhere, people are outraged at what feels like a rigged game -- an economy that won't respond, a democracy that won't listen, and a financial sector that holds all the cards. - Robert Reich