The sculpture 'Non-Violence' at the UN headquarters in New York.

Enforcement of International Law

In the absence of a global police force, the possibilities for the enforcement of international law are limited. However, international law does set out clear consequences for when obligations are violated, both for individuals and states.

Broadly, a distinction can be made between state responsibility and individual responsibility.

State responsibility

Enforcement of international law imposes obligations on both states that violate the law and other states. The norms on state responsibility are therefore comprised of two categories:

  1. Rules relating to all violations of international law;
  2. Elevated level of rules especially directed towards third states when dealing with particularly serious or grave violations of international law.

General rules on state responsibility

The basic principle of state responsibility in international law provides that a state that violates its international obligations must be held accountable. More concretely, the notion of state responsibility means that states that do not respect their international duties are obliged to immediately stop their illegal behaviour and make reparations to those injured by their acts.

The rules on state responsibility clarify when a state can be held responsible for violating its obligations, and what the consequences are of these violations.

Internationally wrongful acts and state responsibility

A state violates international law when it commits an “internationally wrongful act" - a breach of an international obligation that the state was bound by at the time when the act took place. A state has to act in accordance with the treaties it has signed, as well as with the rules of customary international law.

In practice it is not always easy to identify who is committing a violation of international law. Therefore, questions may arise if a state can be held liable for certain acts. For example, may a state be held responsible if its soldiers, in situations of armed conflict, commit rape or other sexual assaults even when they are off duty? When may a state be held responsible for terrorist groups operating from within its territory or when private security firms commit violations?

In general, a state is responsible for all actions of its officials, de facto and de jure. In addition, states have positive obligations to prevent abuses from being committed against people under their jurisdiction. For example, in the event that a life is lost as a result of violence between two gangs, the state may be in violation of its international obligation to respect the right to life if it fails to undertake a serious and effective investigation into the killing.

Most of such determinations can only be made on a case-by-case basis.

Reparations for international law violations

If a state violates international law, it has a responsibility to immediately cease the unlawful conduct and offer appropriate guarantees that it will not repeat them in the future. The state must also make full reparations for the injury caused, including both material and moral damages.

Obligations of third states

Not only states that violate international law have obligations, but others have, too.

Third states violate international law if they aid or assist violations of international law committed by another state. International humanitarian law (IHL), through Common Article 1 of the Geneva Conventions, sets out the obligation on third states to ensure respect for IHL in all circumstances.

Serious violations of international law and state responsibility

International law also sets out obligations that arise when a state commits a serious breach of international law. These obligations are triggered when the serious breach constitutes the violation of a peremptory norm of general international law. Peremptory norms are norms accepted and recognised by the international community of states as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law with the same character.

Third states have elevated obligations where peremptory norms are breached. The seriousness of the violation of a peremptory norm necessitates a collective response to counteract the effects of the breach of international law. These obligations include:

  • Non-recognition;
  • Non-assistance;
  • Cooperate to bring to an end the violation in question.

The rationale for these heightened obligations is the gravity of breaches of peremptory norms which affect the international community as a whole. 

The Geneva Conventions, through its grave breaches regime, sets out specific obligations for third states when grave breaches of IHL occur.

Individual responsibility under international law

Legal consequences of violations of international law are not limited to states. Certain violations of international law can entail individual criminal responsibility. Persons who aid, abet, order, supervise, or jointly perpetrate international crimes can be held individually responsible.

International crimes for which individuals can be held responsible include genocide, crimes against humanity, war crimes (serious violations of IHL), and the crime of aggression.