With wars raging in the Middle East, it seems like a good time to revisit a classic work by Murray Rothbard (1926–1995), the economist, historian, and political philosopher who had a lot to do with the birth and evolution of the modern libertarian movement. His "War, Peace, and the State" is something that all peace advocates — not just self-conscious libertarians — ought to be familiar with.

I love the way Murray opened this essay, originally published in 1963, during the Cold War. (It was later included in his collection Egalitarianism as a Revolt Against Nature and Other Essays in 1974.) He began by agreeing with conservative magazine editor and author William F. Buckley, who had reprimanded the libertarians of their day for spending more time on how to "demunicipalize the garbage collectors" than on big issues like war and peace. Buckley had a point, Murray said, but not quite in the way the conservative icon meant it:

There is a sense in which libertarians have been utopian rather than strategic in their thinking, with a tendency to divorce the ideal system which we envisage from the realities of the world in which we live. In short, too many of us have divorced theory from practice, and have then been content to hold the pure libertarian society as an abstract ideal for some remotely future time, while in the concrete world of today we follow unthinkingly the orthodox "conservative" line. To live liberty, to begin the hard but essential strategic struggle of changing the unsatisfactory world of today in the direction of our ideals, we must realize and demonstrate to the world that libertarian theory can be brought sharply to bear upon all of the world's crucial problems. By coming to grips with these problems, we can demonstrate that libertarianism is not just a beautiful ideal somewhere on Cloud Nine, but a tough-minded body of truths that enables us to take our stand and to cope with the whole host of issues of our day.

So Murray turned to the matter of war and peace, observing with his signature humor, "Although, when he sees the result, Mr. Buckley [a virulent cold warrior] might well wish that we had stayed in the realm of garbage collection."

Murray's subject was war between nation-states — governments — but he believed that such interstate warfare could not be understood without focusing first on individuals and the violent conflicts between them. After all, governments are groups of individuals that have their status as governments in virtue of their specific relationship to their subject populations. There is no independently existing entity called "the state." So Murray wanted to examine "war" between individuals as such, with the intention of applying the derived principles to the matter of interstate war. This is a good approach, because most people who think about these matters treat governments and their wars as things to be judged by special moral principles not applicable to private individuals.

"The fundamental axiom of libertarian theory," he wrote, "is that no one may threaten or commit violence ('aggress') against another man's person or property. Violence may be employed only against the man who commits such violence; that is, only defensively against the aggressive violence of another. In short, no violence may be employed against a non-aggressor." (I discuss how Murray derived this principle here and here.)

From there Rothbard established that an individual who is threatened with aggression or who has already been the victim of aggression (which would include theft or destruction of justly held possessions) may use defensive force, if necessary, to repel the threat or to rectify the damage. For most people, that's uncontroversial. But he went on to emphasize that the victim may not aggress against third parties even if his only purpose is defense against the aggressor.

So the victim may not grab money or other possessions from bystanders or "draft" them into his service. As in all other matters, he must rely on persuasion if he wants goods or services from other people. This gets us close to the subject of the ethics of emergencies — a difficult subject for another time — and Rothbard realized it. He understood that someone might have a good motive for aggressing against an innocent party, but he insisted that this still could not be regarded as anything other than aggression. However, he added this:

We may understand and sympathize with the motives in many of these cases and extreme situations. We may later mitigate the guilt if the criminal comes to trial for punishment, but we cannot evade the judgment that this aggression is still a criminal act, and one which the victim has every right to repel, by violence if necessary.

Murray inched closer to what happens in interstate warfare when he summed up, "To be more concrete, if Jones finds that his property is being stolen by Smith, he has the right to repel him and try to catch him; but he has no right to repel him by bombing a building and murdering innocent people or to catch him by spraying machine gun fire into an innocent crowd. If he does this, he is as much (or more of) a criminal aggressor as Smith is."

The state, of course, is unique in society in that it claims a legal monopoly on the use of aggressive force, beginning with taxation, the most basic government power of all. How does libertarian thinking about freedom and aggression apply to war between states?

The first thing to notice, Murray said, is that when states go to war, they intensify the violations of liberty that they already commit against their own populations. They may raise taxes, enact new regulations, infringe on freedom of the press, and institute military conscription — the draft. If they borrow the money to pay for the war, the resulting debt and the central bank's likely fiat-money expansion will take their own toll by, say, prompting a hike in taxes later to repay the debt or by robbing the population of purchasing power through inflation. Thus, Murray noted, the first acts of aggression that occur in interstate warfare are against each government's respective "home" population.

While Murray did not approve of any government, he recognized that they weren't going anywhere soon. But he wanted aggression minimized in the meantime, and to that end he advised that states "at least confine [their] activities to the area which [they] monopolize." In other words, avoid war against other states.

Interstate war of course also involves aggression against foreign populations as well as against home populations. While one can paint scenarios in which only actually guilty individuals are attacked during a defensive war, things don't often work out that way in the real world. Even "smart" bombs and Hellfire missiles from remotely controlled drones kill people universally recognized as innocent noncombatants. The disgusting term "collateral damage" was coined to whitewash the inevitable and foreseeable killing of innocents during war. (Murray condemned nuclear weapons precisely because they can't even theoretically be pinpointed at aggressors only. Thus he supported nuclear disarmament at the very least.)

These considerations led him to implore that "the people under each State should pressure 'their' respective States not to attack one another, and, if a conflict should break out, to negotiate a peace or declare a cease-fire as quickly as physically possible."

Murray opposed the principle of collective defense, as embodied in the United Nations, because it encourages piling on and the widening of wars — precisely the opposite of the cordoning off of wars that he favored. He also endorsed the old "laws of war," which respected neutrality:

In short, the libertarian tries to induce neutral States to remain neutral in any inter-State conflict and to induce the warring States to observe fully the rights of neutral citizens. The "laws of war" were designed to limit as much as possible the invasion by warring States of the rights of the civilians of the respective warring countries.

As you can see, Murray's concern was to minimize aggression when states go to war if efforts to avoid war fail. He didn't think peace had to wait until the world was libertarian.

In condemning all wars, regardless of motive, the libertarian knows that there may well be varying degrees of guilt among States for any specific war. But the overriding consideration for the libertarian is the condemnation of any State participation in war. Hence his policy is that of exerting pressure on all States not to start a war, to stop one that has begun and to reduce the scope of any persisting war in injuring civilians of either side or no side.

This essay contains much else of interest — on revolution, foreign aid, and more — so I highly recommend it, as well as Murray's other writings on war. I don't say that he anticipated and addressed every hard question. (Here are supplemental readings by Bryan Caplan in which he argues "it is nearly impossible to wage war justly, i.e., without trampling on the rights of the innocent," and his reply to critics.) But "War, Peace, and the State" is a great start.

This column originally appeared at the Future of Freedom Foundation.