The Ethics of War and the Force of Law

The primary aim of The Ethics of War and the Force of Law is to provide a comprehensive critical overview of the current debates in just war theory while proposing a modern theory that offers practical action-guidance.

Key components of this aim include:

Critique of Competing Approaches: The book engages with and corrects what the author considers misinterpretations within traditionalist, Walzerian, and “revisionist” approaches to just war theory.
Emphasis on the Moral Force of Law: A central thesis is that widely accepted laws and conventions of war are partly constitutive of the moral rules that apply in a conflict. This rejects “moral fundamentalism,” which holds that laws must simply follow an immutable morality.
Action-Guidance: By recognizing the moral force of law, the author aims to provide morally accurate and practically effective guidance for conduct in war that is relevant to the real world.
Integration of Disciplines: The work seeks to integrate philosophical analysis with legal scholarship, particularly drawing on criminal law, which the author argues has been largely ignored by other just war theorists.
Expansion of Justifications: The author aims to complement standard analyses of self-defense with other justifications, such as “lesser evil” and emergency justifications, to better explain the ethics of participating in war.

Uwe Steinhoff argues that the traditional ‘Legitimate Authority’ criterion is unnecessary for justifying war because it is either redundant, lacks sound argumentation, or is based on irrational fears. His reasoning includes the following key points:

Redundancy in Theory: Steinhoff asserts that if an action already satisfies criteria like just cause, proportionality, and necessity, adding a requirement for authorization from a higher power is superfluous. He compares this to self-defense, which is justified without needing external authorization if its core conditions are met.
Historical Precedent: He points out that the just war tradition itself is more individualist than often portrayed. Historical figures like Francisco de Vitoria and Melchor Cano acknowledged that individuals or non-supreme entities could legitimately resort to war if a superior was unable or unwilling to provide justice.
Failure of Consequentialist Arguments: Proponents often defend the criterion by claiming that its removal would lead to chaos and anarchy. Steinhoff refutes this, noting that moral permissions themselves have no causal, empirical consequences; rather, the protection of rights against aggressors—even through individual war—is a positive effect.
The “Nemo Iudex” Standard: He rejects the statist argument that “no one should be a judge in their own cause,” pointing out a double standard where states are routinely allowed to be judges in their own causes, such as when deciding to attack other nations or judging their own citizens for crimes against the state.
Inadequacy of Current Defenses: Steinhoff critiques modern scholars like James Turner Johnson and James G. Murphy, arguing their attempts to prioritize “legitimate authority” are based on mere suggestions or unwarranted stipulations rather than compelling philosophical proof.
Subjective Requirements: He suggests that any legitimate work the “authority” criterion might do is already covered by the “right intention” or knowledge requirement, which ensures the agent is aware that objective justificatory circumstances pertain.

The book The Ethics of War and the Force of Law is organized into four main chapters that define war, evaluate the criteria for justifying its use (jus ad bellum), and examine the moral rules of conduct within conflict (jus in bello).

Chapter 1: Introduction and Overview

Dual Objectives: The book aims to provide a critical overview of current just war theory debates and propose a modern theory offering practical action-guidance.
The Moral Force of Law: It argues that widely accepted laws and conventions of war partly constitute the moral rules applicable in conflict, rejecting “moral fundamentalism,” which holds that laws must follow an immutable morality.
Critique of “Revisionism”: The author challenges “revisionist” just war theory, arguing it misinterprets both the just war tradition and the ordinary morality of force it claims to apply.

Chapter 2: What Is War – and Can a Lone Individual Wage One?

Explicating “War”: The author defines war as an action—which can be right or wrong—rather than just a historical event.
Individual War: Contrary to most modern definitions, the author argues that individuals can wage war if they meet specific criteria, such as being engaged in a sustained violent struggle and being opposed in principle to an adversary’s rule.
Definition Criteria: War is defined as a violent struggle involving numerous individual hostilities where parties lack a superior third-party arbiter and the default method is to kill or incapacitate the enemy.

Chapter 3: Jus ad Bellum: Justifying the Use of War

Legitimate Authority: The author rejects this as a necessary condition, arguing it is redundant and often motivated by an irrational fear of chaos.
Just Cause and Right Intention:
- Just cause is redefined as a state of affairs—specifically, a set of conditions where a proportionate war is possible—rather than a specific goal or aim.
- Right intention is interpreted as a knowledge requirement, meaning an agent is justified if they have a justified true belief that objective justificatory circumstances pertain.
Proportionality Subcriteria: The author argues that prospects of success and last resort are not independent requirements but considerations that fall under the broader assessment of proportionality.

Chapter 4: Jus in Bello: Justifying the Use of Force in War

Critique of Revisionist “Ordinary Morality”: The author refutes revisionist accounts, such as Jeff McMahan’s responsibility account and David Rodin’s “bloodless invasion” argument, by demonstrating they rely on idiosyncratic rather than ordinary interpretations of self-defense law.
Justification vs. Liability: He challenges the “justification defeats liability” doctrine, arguing that justified combatants who cause “collateral damage” can still be liable to counter-attack.
Reciprocity and Conventions: A central argument is that the moral rules of war are shaped by reciprocity. Widely accepted conventions (like non-combatant immunity) have moral force because they create mutual expectations and standards of fairness.
Rejecting Moral Fundamentalism: The author criticizes fundamentalist views that morality is “immutable,” arguing instead that humans have the power to devise and improve the morality of war through laws and customs.

The Ethics of War and the Force of Law by Uwe Steinhoff presents a modern theory of just war that emphasizes the moral force of widely accepted laws and conventions. The book aims to provide a critical overview of current debates while offering practical action-guidance that moves beyond what Steinhoff calls “moral fundamentalism”.

Core Philosophical Themes

The Moral Force of Law: Steinhoff argues that existing laws and customs are not just practical heuristics but are partly constitutive of the moral rules that apply in conflict.
Rejection of “Moral Fundamentalism”: The book rejects the view that laws must slavishly follow an immutable, “deep” morality. Human beings have the moral power to devise and improve the morality of war through customs.
Integration of Legal Scholarship: The author draws heavily on criminal law and legal scholarship, particularly domestic justifications like self-defense and necessity, which he argues have been misinterpreted or ignored by other just war theorists.

Critical Analysis of Competing Schools

Steinhoff engages extensively with two primary schools of thought:

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