Randy Barnett has further thoughts. I found this interesting:

I realize that some fraction of radical libertarians, whose opinion I respect, believe that there is no such thing as a just war, but most radical libertarians (including most critics of my WSJ op-ed) allow the legitimacy of a defensive war and oppose only wars of aggression. Some antiwar libertarians who oppose the Iraq war as aggression, for example, supported the war in Afghanistan on "self-defense" grounds. And those who didn't say they would support a war that was truly in self-defense. They simply deny that the war in Iraq fits that description. Yet if they also accept stance (1), as they appear to, then ON THEIR ACCOUNT because a defensive war is waged by an illegitimate government and the rights of innocents were inevitably violated, it too must be opposed.

I've never quite understood the arguments of those who claim that they're not anti-war because they supported the war in Afghanistan, but that they were opposed to removing Saddam Hussein.

Why did they support the war in Afghanistan? Was it, as described above, because it was a "defensive" war? If so, what does that mean? Was it to prevent further attacks? Or was it to avenge 911?

If the latter (and much of the rhetoric seems to indicate that), then it wasn't a defensive war, except possibly in the limited sense that by making an example of the Taliban we could discourage other regimes from similarly harboring our enemies.

If the former, then it was a preemptive war (that is, we were going to remove a regime, to prevent it from supporting any further attacks). But we've been told by this crowd that preemptive wars aren't acceptable. For instances despite many threats made against Israel (and the Great Satan--us) by Iran, and its continuing development of the means with which to carry them out, we are not allowed to go to war with Iran, because that would be "preemptive" and we're supposed to wait for them to strike the first blow, as happened with Afghanistan.

Now it turns out in hindsight that the threat from Iraq was exaggerated (though not as much as many war opponents assume), but at the time, we considered it sufficient to need to be preemptive (not to mention all of the ongoing violations of the UN resolutions and truce agreements that Saddam continued to ignore). In that sense, it was a defensive war. So when war opponents claim that we have a right to defensive wars, but practically only allow it to happen after it's too late to defend ourselves (as occurred with 911), just what do they mean?

Why did they support the war in Afghanistan? Was it, as described above, because it was a "defensive" war? If so, what does that mean? Was it to prevent further attacks? Or was it to avenge 911?

If the latter (and much of the rhetoric seems to indicate that), then it wasn't a defensive war, except possibly in the limited sense that by making an example of the Taliban we could discourage other regimes from similarly harboring our enemies.

Which is an entirely sufficient reason. Revenge is a very powerful motive to humans, and I suspect the desire for revenge evolved exactly because it discourages further attacks against someone so inclined.

Also, unless you are fundamentally opposed to ANY military action (which supporters of war in Afghanistan clearly are not), then "taking fight to the enemy" after having been attacked, is an entirely sensible course of action.

I disagree with the interpretation of the Afghanistan invasion as preemptive. The Taliban clearly was working with Al Qaeda and providing great support to an enemy which attacked the US. I however see the Iraqi invasion as a poorly justified preemptive war.

Also, unless you are fundamentally opposed to ANY military action (which supporters of war in Afghanistan clearly are not), then "taking fight to the enemy" after having been attacked, is an entirely sensible course of action.

But what does "taking the fight to the enemy" mean?

And who is the enemy? Again, do we have to wait until we are actually attacked before we recognize an enemy?

I disagree with the interpretation of the Afghanistan invasion as preemptive.I disagree with the interpretation of the Afghanistan invasion as preemptive.

Then what was its purpose?

To eliminate a base of support for an enemy at war with the US, namely Al Qaeda and its allies, the Taliban.

Saddam was funding terrorists in Israel (his famous Jew bounty) and Iraq was a known "resting" place for the world's terrorists including Carlos the Jackal et al. Oh yeah and how about that training camp for terrorists North of Baghdad?

It's only preemptive in hindsight but then again...why would describe Iraq as a preemptive action? We TOLD 'ol Saddam to behave according to the resolutions he agreed to from the previous visit. He didn't and he got spanked for it.

Well, I've said here in Comments many times that we had plenty of good reasons to invade Iraq. Problem is the administration only locked on to the no-brainer (WMD). I recall they enumerated some others, but they obviously set themselves up for trouble with the WMD argument.

Number One, I think we wanted to show after 9/11 that the sleeping giant had been awakened, and the old way of doing things in the Middle East was OVER. Saddam was removed to show we meant business. Not a bad idea, but the follow-through has clearly not been well managed until recently.

What surprised (and disgusted) me after 9/11 was how many people opposed invading Afghanistan. And does anyone recall how many in the MSM were starting to claim we were getting "bogged down" in a "quagmire" after only three weeks in country? And how everything finally came together the following week?

After the 1st Gulf War, I became very concerned that our almost effortless victory would lull people into thinking war was now simple, easy and quick. That fear has apparently turned out to be well-founded.

What the heck is Barnett doing mixing up libertarianism with thoughts on the objective ethical justification for wars? That's bizarre.

Surely one of the fundamental tenets of libertarianism is that it's very difficult -- often impossible -- to decide whether a given action is moral or immoral on some objective scale that works for everyone. Surely it is from this fundamental doubt of the ability of mere mortals to decide what is Right and Good for everyone that the essential theme of libertarianism springs, id est, liberty: the belief that each man should, to the maximum extent possible, be free to do what he thinks is right according to his own reasoning.

Why prize individual liberty -- the right to defy the majority -- unless you think it's probably impossible to noodle out objectively for everyone when it is, and is not, moral to go to war?

I think the solid libertarian looks for way to make warfare a matter, as much as possible, of individual choice, as opposed to something people can be dragged into against their will by a (possibly deluded) majority. He's probably as neutral on war qua war as he is on drug use or prostitution.

The way I look at it, Bush didn't require any justification at all to go to war with Iraq. In fact, the US was still at war with Iraq in January of 2001, and Iraq had violated the terms of the ceasefire of the Persian Gulf war many times during the Clinton administration. The resumption of hostilities should have occurred years earlier.

I believe there were several mistakes made. First of all was Bush's attempt to go through the UN. He didn't need their support and already had every legal right to resume the Persian Gulf war, and piddling around with the UN merely served to telegraph US intentions to Iraq.

Secondly, the unnecessary forced connection between Iraq and the war on terror. Sure, there were plenty of connections there, but the war on terror was simply not needed as a justification , and only served to muddy the issue for the american public.

Third, the "war on terror" itself. Countries can only logically declare war on other countries. Declaring war on an emotional state is ludicrous. Calling it the war on terrorism is marginally better, as it is thus a war on an ideology - but again, that ideology is supported by several countries, and it is those countries that the US wars with, not the ideology.

Terrorism wasn't supported by any of the countries that we invaded, it was supported by a small minority of nutcases within those countries who managed to operate because of ineffective law enforcement. For some reason this current administration of the US government thought that the best response to this problem was to remove ALL law enforcement.

Barnett's post is excellent. He adopts the same tone that an adult might use in explaining the facts of life to a clever but obstinate child, but this is perhaps a necessary tactic given his naive audience.

What good is adhering to libertarian dogma if by doing so you allow your imperfect-but-relatively-decent society to be vanquished by barbarians? Surely that's at least as important an outcome to avoid as is any home-grown statism. Wisdom in this case means recognizing that our choices aren't between perfect and good but rather between livable and terrible.

Johnathan, "libertarian dogma" is an oxymoron. It is a pity that more libertarians don't realize this.

It's more a pity that people who don't understand that claim to be libertarians.

Terrorism wasn't supported by any of the countries that we invaded, it was supported by a small minority of nutcases within those countries who managed to operate because of ineffective law enforcement.

This seems a little glib and clueless, for three reasons:

(1) The Taliban were not merely failing to suppress OBL and al Qaeda in Afghanistan -- they were actively supporting them.

(2) No one in their right mind could call the Hussein regime in Iraq "ineffective" at law enforcement. They were all about law enforcement, often very brutal and generally very effective law enforcement. The problem was what the "law" that they were enforcing was. Not very nice laws. Not consistent with American interests.

(3) You seem a little muddled about what "support" means. You're surely correct that terrorism was actively committed by only a tiny minority of people in either Afghanistan or Iraq (or Pakistan, Saudi Arabia, et cetera). But you might as well have pointed out that only a tiny percentage of German citizens worked the death camps in the 1940s. Neither fact is really relevant to the question of "support."

What you need to ask is: does enough of the country's command-and-control structure (however you want to parse that) positively contribute to the activities of the bad people, enough to justify destroying that structure? It doesn't much matter how they contribute, does it? If their "contribution" is turning a blind eye to what's up in their own backyard, well, that's "support" according to most people.

(4) Your biggest problem is that you're arguing from a purely theoretical perspective: this action should cause this result, because of logical argument blah blah et cetera. Yet you've got plenty of empirical facts and correlations by now about US foreign policy and terrorism. Perhaps you should use them, instead? For example, what is the correlation between "law enforcement" policy (e.g. under Clinton in the 90s) and subsequent terror acts? Compare to "aggressive Texas cowboy" policy under GWB and subsequent terror acts. Which has been, empirically speaking, more successful? Cold facts trump the most elegant and persuasive theory every time, you know.

Johnathan, "libertarian dogma" is an oxymoron. It is a pity that more libertarians don't realize this.

Word games. Libertarian dogma is the dogma of libertarians who assert, for example, that "no initiation of force" means that preemptive war is necessarily immoral. My response, as above, is: What's moral about being so fastidious about the use of force that you fail to defend your society effectively against people who would enslave you? The point about political philosophy, including libertarianism, is to make life better according to the values that you think are important. Libertarians value freedom very highly. Freedom is not advanced by interpreting libertarian principles so rigidly that you lose the ability to respond to existential threats. This is what I mean by libertarian dogmatism.

My experience in reading and interacting with libertarians is that many of them are dogmatic.

Yet you've got plenty of empirical facts and correlations by now about US foreign policy and terrorism. Perhaps you should use them, instead?

Empirically observed fact: 125,000 troops are not enough to enforce the peace in Iraq. New York has 50,000 police officers and they barely manage even without the daily shelling.

If the US cared about enforcing the peace they would have put 300,000+ boots on the ground. This was recommended (loudly) by the Pentagon before the war but fell on deaf ears.

Empirically observed fact: 125,000 troops are not enough to enforce the peace in Iraq.

Define "peace," please. By me Iraq is at peace. The death rate via what amounts to continual intergang (Shia/Sunni) violence is modest by historical standards, or the standards of the region, and does not seem to seriously interfere with the functioning of government or civil society.

Iraq is generally, with minor and scattered exceptions, functioning economically and socially. People are employed, inflation is high but not insane, the dinar is not becoming worthless, the government is suspected but not utterly and cynically distrusted, most (if not 100% of) ideological struggles are settled politically and not violently, investment and economic growth are in progress, buildings are going up, kids are going to school, et cetera and so forth.

Violent death is a tragedy, yes, but it is not so much of a tragedy that it blackens every aspect of a society. The fact that there is murder in Los Angeles -- quite a lot of it -- does not mean Los Angeles is a worthless stain on the planet. (It is, but for other reasons.)

I think it is absurdly myopic to define an entire society by how many of its people die violently every day. By that silly metric, most of Europe for most of its history was an utter failure.

Furthermore, the idea that there must be zero deaths by criminal violence before you say a country is "at peace" is just a straw man -- an impossible goal -- set up by those who have decided in advance and on theoretical grounds that the US intervention in Iraq is a failure. It need not occupy the attention of serious observers.