What Are Countermeasures in International Law, and What Are the Requirements and Limits for Taking Them?

Japanese Attorney at Law - Bengoshi L.L.

• 7 min read

In the decentralized international legal system, where no overarching global police force or compulsory judicial enforcement mechanism exists, states sometimes resort to self-help measures to address breaches of international law by other states. One such category of measures, strictly regulated by international law, is "countermeasures." These are acts undertaken by an injured state that would otherwise be unlawful but are considered justified as a response to a prior internationally wrongful act by another state, aimed at inducing that state to comply with its international obligations. This article explores the nature of countermeasures, the stringent conditions for their lawful application, and the significant limitations imposed by international law.

Understanding Countermeasures: Nature and Purpose

Countermeasures, as defined by the International Law Commission's Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), are characterized by several key features:

  1. Response to a Prior Wrongful Act: A countermeasure is only permissible if taken in response to an existing internationally wrongful act committed by the target state against the state taking the countermeasure. This prior breach is the fundamental prerequisite.
  2. Inducement of Compliance: The primary purpose of countermeasures is not punitive. Instead, they are aimed at inducing the responsible state to comply with its international obligations, specifically its obligations of cessation of the wrongful act and to make reparation for any injury caused (ARSIWA Article 49).
  3. Temporary Nature: Countermeasures are, by their nature, temporary. They must be terminated as soon as the responsible state has complied with its obligations concerning the initial wrongful act.
  4. Otherwise Unlawful Acts: The acts taken as countermeasures would, in themselves, constitute a breach of an international obligation owed to the target state. It is the prior wrongful act by the target state, and compliance with the rules governing countermeasures, that precludes the wrongfulness of the countermeasure (ARSIWA Article 22).

Distinction from Other Measures:
It is crucial to distinguish countermeasures from:

  • Retorsion: These are unfriendly but lawful acts taken by a state in response to another state's lawful or unlawful conduct (e.g., severing diplomatic relations, withdrawing voluntary aid, imposing non-discriminatory trade restrictions not otherwise prohibited by treaty). Since retorsion involves acts that are not internationally wrongful, it does not require the same legal justification as countermeasures.
  • Armed Reprisals/Use of Force: Historically, "reprisals" could include the use of armed force. However, modern international law, particularly the UN Charter's prohibition on the threat or use of force (Article 2(4)), forbids armed reprisals. Countermeasures must be non-forcible. The shift in terminology from "reprisal" to "countermeasure" partly reflects this prohibition of armed measures in this context.
  • Sanctions by International Organizations: Measures decided by international organizations, such as sanctions imposed by the UN Security Council, are based on the constituent treaty of that organization and are distinct from unilateral countermeasures taken by an individual state.

Countermeasures essentially represent a form of self-help available to an injured state. Given the lack of a centralized enforcement system, they allow a state to exert pressure on a wrongdoing state to return to a path of legality. However, because they involve a state taking the law into its own hands, their application is subject to strict conditions and limitations to prevent abuse and escalation of disputes.

Conditions and Limitations for Lawful Countermeasures

The lawfulness of countermeasures hinges on satisfying several rigorous conditions, largely codified in the ILC's ARSIWA.

A. Existence of a Prior Internationally Wrongful Act

This is the sine qua non of countermeasures. The state taking countermeasures must have been injured by an internationally wrongful act of the target state. If the target state did not commit a prior wrongful act, the "countermeasure" itself constitutes an internationally wrongful act, for which the acting state will be responsible. This means the state resorting to countermeasures acts at its own risk regarding the initial legal assessment.

B. Purpose and Temporariness

As mentioned, countermeasures must be aimed at inducing the responsible state to comply with its international obligations (cessation and reparation). They are not intended to be punitive. Furthermore, they must be temporary in nature and "as far as possible, be taken in such a way as to permit the resumption of performance of the obligations in question" (ARSIWA Article 49(3)). Once the responsible state complies, the countermeasures must cease.

C. Procedural Requirements (ARSIWA Article 52)

To prevent abuse and encourage peaceful resolution, certain procedural steps are generally required before countermeasures can be lawfully taken:

  1. Call to Comply (Notification of Claim): The injured state must first call upon the responsible state to fulfill its obligations of cessation and reparation. This gives the responsible state an opportunity to rectify the situation.
  2. Notification of Decision to Take Countermeasures and Offer to Negotiate: The injured state must notify the responsible state of any decision to take countermeasures and offer to negotiate with that state. This requirement underscores the principle that countermeasures should be a last resort.
  3. Exception for Urgent Countermeasures: Notwithstanding the notification requirement, the injured state may take such urgent countermeasures as are necessary to preserve its rights. This allows for immediate action when waiting would render the countermeasures ineffective.
  4. Suspension Pending Dispute Settlement: Countermeasures may not be taken, and if already taken must be suspended without undue delay, if:
    • The internationally wrongful act has ceased, AND
    • The dispute is pending before a court or tribunal which has the authority to make decisions binding on the parties.
      This rule, reflecting the principle that dispute settlement mechanisms should be preferred over unilateral measures, was highlighted in the Air Service Agreement Case (United States v. France) (Arbitral Award, December 9, 1978), where the tribunal noted that once a dispute is submitted to a tribunal capable of ordering interim measures, the legitimate purpose of countermeasures may be served by those judicial processes.
      However, this obligation to suspend countermeasures does not apply if the responsible state fails to implement the dispute settlement procedures in good faith (ARSIWA Article 52(4)).

D. Substantive Limitations (ARSIWA Article 50)

Even if procedurally justified, countermeasures are subject to fundamental substantive limitations:

  1. Prohibition of the Threat or Use of Force: Countermeasures must not involve the threat or use of force as prohibited by the UN Charter. This is a cardinal rule.
  2. Fundamental Human Rights: Countermeasures must not infringe upon obligations for the protection of fundamental human rights. States cannot violate basic human rights as a means of inducing compliance from another state.
  3. Obligations of a Humanitarian Character Prohibiting Reprisals: Countermeasures cannot affect obligations of a humanitarian character that prohibit reprisals. This refers to specific prohibitions found in international humanitarian law against reprisals targeting certain protected persons or objects in armed conflict.
  4. Other Jus Cogens Norms: Countermeasures may not affect other obligations under peremptory norms of general international law (jus cogens). These are fundamental norms of the international community from which no derogation is permitted (e.g., prohibitions of genocide, slavery, apartheid).
  5. Diplomatic and Consular Inviolability: Countermeasures cannot affect obligations to respect the inviolability of diplomatic or consular agents, premises, archives, and documents. The ICJ in the Case Concerning United States Diplomatic and Consular Staff in Tehran (United States of America v. Iran) (Judgment, May 24, 1980) emphasized that diplomatic law itself provides the remedies for breaches of diplomatic obligations, suggesting it operates as a "self-contained regime" in this respect.

E. Proportionality (ARSIWA Article 51)

Countermeasures must be "commensurate with the injury suffered, taking into account the gravity of the internationally wrongful act and the rights in question". This principle of proportionality is crucial to prevent countermeasures from becoming excessive or punitive.
Assessing proportionality can be challenging. It involves a qualitative, rather than purely quantitative, judgment. The ICJ in the Gabcíkovo-Nagymaros Project (Hungary/Slovakia) case (Judgment of September 25, 1997) affirmed that an essential condition for a countermeasure to be lawful is that it must be proportionate to the injury suffered, taking into account the rights in question and the gravity of the initial wrongful act. The effects of a countermeasure must not be "manifestly disproportionate" to the injury.

The Concept of "Self-Contained Regimes"

Some international treaties create their own specific mechanisms for addressing breaches of their provisions. Examples include the dispute settlement system of the WTO or specific compliance mechanisms in certain human rights or environmental treaties. In such cases, the question arises whether these "self-contained regimes" exclude the right of states to resort to general countermeasures under customary international law.
The prevailing view is that while states should first utilize the special remedies provided by such regimes, this does not necessarily mean that general countermeasures are entirely precluded if those specialized mechanisms prove ineffective in securing compliance. However, if a treaty explicitly prohibits countermeasures or provides an exclusive set of remedies, then states parties would be bound by that specific arrangement.

Countermeasures by States Other Than the Directly Injured State

Traditionally, the right to take countermeasures has been understood as belonging to the state directly injured by the internationally wrongful act. However, a complex and evolving issue is whether states not directly injured may take countermeasures in response to certain types of breaches, particularly breaches of obligations owed to the international community as a whole (obligations erga omnes) or to a group of states (obligations erga omnes partes), such as those arising from peremptory norms or concerning common interests like fundamental human rights or global environmental protection.

State practice in this area is sparse, ambiguous, and often controversial. Examples sometimes cited (such as sanctions against South Africa during apartheid, or against Argentina during the Falklands/Malvinas conflict) were often not explicitly justified as "countermeasures" under international law by the acting states, or were taken pursuant to UN Security Council resolutions or regional arrangements.

The ILC's ARSIWA Article 54 addresses this issue cautiously. It does not explicitly authorize or prohibit such measures by states other than the injured state. Instead, it is a "saving clause," stating that the chapter on countermeasures does not prejudice the right of any state, entitled under Article 48(1) to invoke the responsibility of another state, to take "lawful measures" against that state to ensure cessation of the breach and reparation in the interest of the injured state or of the beneficiaries of the obligation breached. The term "lawful measures" is deliberately chosen to avoid prejudging whether such measures would qualify as countermeasures in the traditional sense, or what other forms of lawful action might be available.

The general view remains that unilateral countermeasures by third states, particularly outside a framework of collective security or specific treaty authorization, are problematic due to the high risk of abuse, escalation, and undermining the stability of international relations. Ensuring compliance with obligations erga omnes is often seen as best addressed through collective mechanisms (like the UN) or specific treaty regimes that may provide for collective responses.

Conclusion

Countermeasures in international law are a form of self-help, a tool available to an injured state to induce a wrongdoing state to return to compliance with its international obligations. They reflect the decentralized nature of the international legal system but are not a license for arbitrary action. International law imposes strict conditions and limitations on their use—including the necessity of a prior wrongful act, the purpose of inducing compliance, procedural requirements like notification and an offer to negotiate, substantive prohibitions against certain types of measures (especially the use of force and violations of fundamental human rights or jus cogens norms), and the overarching principle of proportionality.

While essential for upholding international law in the absence of robust centralized enforcement, countermeasures are a remedy of last resort. Their application underscores the delicate balance between a state's right to protect its interests and the international community's interest in maintaining peace and stability and preventing the abuse of unilateral measures. The evolving discourse, particularly concerning responses to breaches of community obligations, highlights the ongoing development of this complex area of international law.