Defensive Force and Durable Freedom: Adapting Principles to Global Challenges
In a thought-provoking article, my colleague Patrick Carroll offered his insights into the challenges of developing a coherent libertarian foreign policy. His emphasis on the immorality of forcing taxpayers to fund wars they oppose and the dangers of escalating local conflicts into global conflagrations is well-taken. However, I believe libertarians would benefit from engaging more deeply with some of the difficult moral and strategic considerations that we must grapple with when it comes to military action.
In his piece “Libertarian Problems,” David Friedman illustrates the hard questions that test the limits of libertarian principles. Friedman presents a series of thought experiments and scenarios that challenge simplistic applications of the non-aggression principle. He argues that in extreme situations, such as a mass murderer hiding among innocent civilians or an existential threat posed by foreign aggressors, a principled libertarian position may require actions that would otherwise be considered violations of individual rights. While Friedman is careful not to endorse any particular departure from libertarian principles, his analysis highlights the need for nuanced moral reasoning when faced with serious dilemmas.
In the case of war, we must distinguish between condemning specific war crimes and condemning all wars as inherently criminal. Classical libertarian thinkers, while generally critical of war, have recognized that military action may be necessary in certain circumstances, particularly in defense of individual rights and liberties against aggressors.
As Leonard Read highlights in “Anything That’s Peaceful,” defensive force is always a justified reaction to aggression or violence:
Defensive force is never an initial action. It comes into play only secondarily, that is, as the antidote to aggressive force or violence. Any individual has a moral right to defend his life, the fruits of his labor (that which sustains his life), and his liberty—by demeanor, by persuasion, or with a club if necessary. Defensive force is morally warranted.
Military action, while a significant leap from Read’s individual to collective action, takes place when threats are so severe and widespread that political action becomes justified—as when a large group of people face existential dangers that, under given circumstances, cannot be effectively addressed through individual or private means alone.
Carroll’s thought experiment involving a serial killer hiding among innocent civilians sheds light on the difficult moral calculations inherent to extreme situations. But it falls short of fully capturing the nuanced considerations of proportionality and imminent threat that libertarian theories of justice must grapple with in real-world scenarios, such as when an aggressor poses an immediate, existential danger. Consider the case of Hamas, a terrorist organization whose foundational goal is the destruction of Israel as a nation. When a nation, such as Israel, is faced with the aftermath as well as credible threats of renewed catastrophic attacks, a targeted military response that risks some collateral damage could be justified if it is the only means to prevent a far greater loss of innocent life.
The October 7th attack was not merely an isolated incident, but part of a broader strategy aimed at denying Israel the right to exist. Hamas’s goal of aligning other nations in the region to destroy Israel creates a multi-front existential threat to Israel. Additionally, there is a false equivalence between a nation employing a defensive shield to protect its civilians and a group that uses civilians as a defensive shield. As Friedman writes:
“The Hamas troops are embedded in the civilian population of Gaza. There is no way the Israeli military can fight them that does not kill civilians. Arguably the civilians are a deliberate human shield, with Hamas managing the conflict to get civilians killed in order to put pressure on Israel to abandon the war; certainly Hamas makes a point of announcing their estimates of how many women and children have been killed and their foreign supporters use those figures to accuse Israel of genocide.”
This understanding behind the morality of defensive force is also relevant in the context of the ongoing war in Ukraine. The threat of Russian nuclear aggression and the potential for an autocratic regime to dominate European democracies poses serious risks to individual liberty. As Ludwig von Mises argued in “Omnipotent Government,” there are times when military resistance to totalitarian conquest is necessary to preserve a free society. Mises wrote:
[Pacifism] is not only futile but harmful. It paralyzes the forces of defense… An aggressor cannot be made to desist from his aggression by exhortations and moralizings. He will desist only if he is confronted by a power strong enough to prevent his advance… Only armed resistance can stop the aggressor.
While Mises was no warmonger, he recognized that principled opposition to war must be balanced against the need to defend liberal civilization from existential threats. In the context of Eastern Europe in the 1940s, Mises saw Nazi and Soviet aggression as a fundamental danger to human liberty that had to be resisted by force of arms. A similar argument could be made today with regard to the threat posed by Russian imperialism to the democratic nations of Europe, or Israel’s defensive actions against Hamas attacks.
“If your response to the human shield problem,” writes Friedman, “is that killing an innocent shield violates the victim’s rights so you should never do it, you are at the mercy of any opponent willing to follow the Hamas strategy or any serious nuclear power.”
A mature libertarian approach to foreign policy recognizes that preserving individual liberty sometimes requires defensive action to confront existential threats, even as it maintains a healthy skepticism towards interventionism and empire-building. Acknowledging the occasional necessity of defensive force while remaining vigilant against the misuse of military power can help libertarians chart a course that maximizes human freedom and minimizes unjust aggression in an imperfect world.
Editor’s note: This piece originally was published by the Foundation for Economic Education.