Countermeasures in International Law

Meaning of Countermeasures

Countermeasures are measures taken by an injured State in response to a prior internationally wrongful act of another State, with the purpose of inducing that State to comply with its international obligations.

Countermeasures are recognised as a circumstance precluding wrongfulness under Article 22 of the International Law Commission’s Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA).

They are further regulated by Articles 49–54 ARSIWA.

The basic idea is:

State A commits an internationally wrongful act

↓

State B is injured

↓

State B takes a lawful countermeasure

↓

Wrongfulness of State B’s otherwise non-conforming conduct may be precluded

Countermeasures are therefore an exceptional response mechanism, not a general right of retaliation or punishment.

Article 22 ARSIWA

Article 22 provides that the wrongfulness of an act of a State that is not in conformity with an international obligation owed to another State is precluded when and to the extent that the act constitutes a lawful countermeasure taken against that other State.

The key expression is:

“Lawful countermeasure”

A State cannot simply describe an otherwise unlawful act as a countermeasure. The measure must satisfy the conditions established under international law.

Purpose of Countermeasures

The principal purpose of countermeasures is compliance, not punishment.

Under Article 49 ARSIWA, an injured State may take countermeasures against a State responsible for an internationally wrongful act in order to induce that State to comply with its obligations concerning:

• cessation of the wrongful act; and
• reparation.

Therefore:

Countermeasure ≠ Punishment

Countermeasure = Pressure to secure compliance

Basic Conditions for Countermeasures

For a countermeasure to be lawful, several conditions must be satisfied.

Prior Internationally Wrongful Act

There must generally be a prior internationally wrongful act committed by the State against which the countermeasure is directed.

The countermeasure cannot ordinarily be used simply because a State believes that another State may violate an obligation in the future.

There must be an established legal basis for the response.

Countermeasure Must Be Directed Against the Responsible State

Under Article 49, countermeasures are taken against the State responsible for the internationally wrongful act.

A State cannot normally take countermeasures against an unrelated third State merely because that third State is politically associated with the responsible State.

Purpose Must Be to Induce Compliance

The countermeasure must be aimed at inducing the responsible State to comply with its international obligations.

The purpose is therefore remedial and coercive rather than punitive.

Proportionality

Article 51 ARSIWA requires countermeasures to be commensurate with the injury suffered, taking into account the gravity of the internationally wrongful act and the rights in question.

Thus, a countermeasure cannot be excessive in relation to the original wrongful act.

Serious breach → potentially stronger response

Minor breach → disproportionate response cannot be justified

Proportionality is one of the most important requirements governing countermeasures.

Article 50 – Obligations Not Affected by Countermeasures

Countermeasures are subject to important limitations.

Under Article 50 ARSIWA, countermeasures must not affect certain fundamental obligations.

In particular, countermeasures cannot affect:

• the obligation to refrain from the threat or use of force as embodied in the UN Charter;
• obligations for the protection of fundamental human rights;
• obligations of a humanitarian character prohibiting reprisals;
• other obligations under peremptory norms of general international law.

They must also respect certain obligations relating to diplomatic and consular inviolability.

Important Principle

A State cannot justify the use of prohibited force merely by calling it a countermeasure.

Therefore:

Countermeasures are not a licence to use military force.

Article 49 – Limits of Countermeasures

Article 49 contains important limitations concerning the scope and purpose of countermeasures.

Countermeasures:

• may be taken only against the responsible State;
• must be directed towards inducing compliance;
• are limited to the extent necessary for that purpose;
• must be terminated once the responsible State complies with its relevant obligations.

This reinforces their temporary and conditional character.

Article 52 – Conditions Relating to Notification

Before taking countermeasures, the injured State must generally:

• call upon the responsible State to fulfil its obligations; and
• notify the responsible State of its decision to take countermeasures.

The injured State must also offer to negotiate with the responsible State.

However, Article 52 recognises circumstances in which urgent countermeasures may be taken where necessary to preserve the injured State’s rights.

Article 53 – Termination of Countermeasures

Countermeasures must cease when the responsible State has:

• complied with its obligations concerning cessation of the wrongful act; and
• fulfilled its obligations concerning reparation, as applicable.

This reflects the principle that countermeasures are temporary instruments of inducement, not permanent sanctions.

Article 54 – Measures Taken by Other States

Article 54 preserves the right of States entitled to invoke responsibility under Article 48 to take lawful measures to ensure cessation and reparation.

This provision is important in situations involving obligations owed to the international community.

However, the legal framework concerning measures by States other than an injured State is more complex than the ordinary bilateral countermeasure regime.

For examination purposes, distinguish:

Injured State → ordinary countermeasures

Other States → Article 48/54 framework

Countermeasures and Reprisals

The modern law generally distinguishes countermeasures from the older concept of reprisals.

Historically, reprisals could encompass a broader range of coercive responses.

Modern countermeasures are governed by stricter legal limitations and cannot involve prohibited force.

Therefore, contemporary international law uses the concept of countermeasures within the framework of State responsibility.

Countermeasures and Retorsion

Countermeasures must also be distinguished from retorsion.

Retorsion

Retorsion consists of an unfriendly but lawful act taken in response to another State’s conduct.

Examples may include:

• withdrawal of diplomatic personnel;
• reduction of diplomatic relations;
• suspension of certain voluntary cooperation.

Because the act itself is lawful, it does not require a circumstance precluding wrongfulness.

Countermeasure

A countermeasure involves conduct that would otherwise be inconsistent with an international obligation owed to the responsible State, but whose wrongfulness is precluded because the strict requirements for countermeasures are satisfied.

Easy distinction:

Retorsion = unfriendly but lawful

Countermeasure = otherwise unlawful but justified under strict conditions

Countermeasures vs Self-Defence

Countermeasures	Self-Defence
Articles 22 and 49–54 ARSIWA	Article 21 ARSIWA / Article 51 UN Charter
Response to a prior internationally wrongful act	Response to an armed attack
Generally does not permit use of force	May involve lawful use of force
Purpose is to induce compliance	Purpose is defensive
Subject to Article 50 limitations	Subject to UN Charter and customary law
Proportionality is required	Necessity and proportionality are required

A countermeasure should not be used as a substitute for the law of self-defence.

Countermeasures vs Necessity

Countermeasures	Necessity
Article 22	Article 25
Responds to another State’s prior wrongful act	Responds to a grave and imminent peril
Directed against the responsible State	Protects an essential interest
Purpose is to induce compliance	Purpose is to safeguard the essential interest
Governed by Articles 49–54	Governed by Article 25
Requires a prior wrongful act	Does not require another State to have committed a prior wrongful act

Countermeasures vs Force Majeure

Countermeasures	Force Majeure
Article 22	Article 23
Deliberate response by a State	Result of an external event
Requires prior wrongful act by another State	Requires irresistible force or unforeseen event
Intended to induce compliance	Performance is materially impossible
Subject to strict legal conditions	State must not have caused the situation or assumed the risk

Proportionality of Countermeasures

Proportionality is central to the legality of countermeasures.

The assessment considers factors such as:

• gravity of the original wrongful act;
• injury suffered;
• rights involved;
• interests affected;
• nature and consequences of the countermeasure.

The requirement does not necessarily mean that the countermeasure must be identical to the original wrongful conduct.

Rather, the response must remain commensurate with the injury and circumstances.

Countermeasures Must Not Be Punitive

The distinction between inducement and punishment is critical.

Suppose State A breaches a treaty obligation owed to State B.

State B cannot simply impose an unlimited penalty on State A because it believes punishment is deserved.

The countermeasure must remain connected to the objective of inducing compliance with the relevant international obligations.

Therefore:

Original breach → Countermeasure → Compliance

not:

Original breach → Punishment

Countermeasures and Human Rights

Article 50 places important limits on countermeasures affecting obligations concerning fundamental human rights.

A State cannot use countermeasures as an excuse to disregard fundamental human rights obligations.

This reflects the fact that countermeasures operate within, and not outside, the broader framework of international law.

Countermeasures and Diplomatic Relations

Article 50 also protects certain obligations concerning diplomatic and consular inviolability.

This is particularly significant because diplomatic relations are governed by specialised international rules.

A State cannot simply disregard diplomatic or consular protections on the ground that it is responding to another State’s wrongful conduct.

Countermeasures and Jus Cogens

Countermeasures cannot violate obligations arising from peremptory norms of general international law (jus cogens).

Article 50 expressly refers to obligations arising under peremptory norms.

Thus:

Jus cogens → higher limitation

Countermeasure cannot override jus cogens

Gabčíkovo-Nagymaros Project

In Gabčíkovo-Nagymaros Project (Hungary/Slovakia), the ICJ considered the law relating to countermeasures.

The case is particularly important because the Court examined whether Hungary and Slovakia could rely upon countermeasures to justify conduct affecting their treaty relationship.

The Court emphasised that countermeasures are subject to conditions under international law, including proportionality.

Exam relevance:

• countermeasures;
• proportionality;
• prior wrongful conduct;
• relationship between countermeasures and treaty obligations.

Air Services Agreement Arbitration

The Air Services Agreement Arbitration (United States v France) is an important arbitral authority concerning countermeasures.

The tribunal considered the legality and proportionality of measures taken in response to alleged non-performance of international obligations.

The decision is frequently discussed in relation to the principle that a response should bear a reasonable relationship to the alleged breach.

Exam relevance:
Useful for proportionality and countermeasures.

Nicaragua v United States

In Military and Paramilitary Activities in and against Nicaragua, the ICJ considered the relationship between unlawful force and alleged responses.

The case is particularly important for distinguishing countermeasures from self-defence and reinforcing the prohibition on the use of force.

A State cannot circumvent the prohibition on force by simply characterising its action as a countermeasure.

Simple Flowchart

International obligation owed between States

↓

State A commits an internationally wrongful act

↓

State B is entitled to invoke responsibility

↓

State B calls upon State A to comply

↓

Notification + offer to negotiate

↓

Countermeasure taken

↓

Must be directed against responsible State

↓

Purpose = induce compliance

↓

Proportionate

↓

Does not violate protected obligations under Article 50

↓

Responsible State complies

↓

Countermeasure terminates

Countermeasure Checklist

Before treating a measure as lawful, ask:

Was there a prior internationally wrongful act?

↓

Is the measure directed against the responsible State?

↓

Is the purpose to induce compliance?

↓

Is the measure proportionate?

↓

Were the procedural requirements satisfied?

↓

Does it respect Article 50 limitations?

↓

Has the countermeasure remained temporary?

If the answer to these questions is yes, the measure has a stronger basis for qualification as a lawful countermeasure.

Quick Revision

Point	Rule
Basic provision	Article 22 ARSIWA
Detailed rules	Articles 49–54 ARSIWA
Trigger	Prior internationally wrongful act
Target	Responsible State
Purpose	Induce compliance
Proportionality	Article 51
Obligations protected	Article 50
Procedural requirements	Article 52
Termination	Article 53
Other States	Article 54
Leading case	Gabčíkovo-Nagymaros
Other authority	Air Services Agreement Arbitration
Force prohibited?	Countermeasures cannot justify prohibited force
Punishment?	Not their lawful purpose
Jus cogens	Cannot be violated through countermeasures

Key Exam Points

• Article 22 ARSIWA recognises countermeasures as a circumstance precluding wrongfulness.
• Detailed rules appear in Articles 49–54 ARSIWA.
• Countermeasures require a prior internationally wrongful act.
• They are directed against the responsible State.
• Their purpose is to induce compliance, not punish.
• Countermeasures must be proportionate under Article 51.
• Article 50 protects fundamental human rights, humanitarian obligations, the prohibition on force and jus cogens, among other protected obligations.
• Article 52 contains important procedural requirements.
• Countermeasures must be terminated when the relevant compliance requirements are met.
• Retorsion is different because it involves conduct that is already lawful.
• Countermeasures cannot be used as a substitute for self-defence.
• Gabčíkovo-Nagymaros is a leading ICJ authority.
• Air Services Agreement Arbitration is important for proportionality.

Conclusion

Countermeasures are an important mechanism within the law of State responsibility through which an injured State may respond to another State’s internationally wrongful act. Their purpose is not to punish but to induce compliance with the responsible State’s obligations concerning cessation and reparation.

Because countermeasures may themselves involve conduct that would ordinarily violate an international obligation, international law imposes strict safeguards. They must be directed against the responsible State, remain proportionate, satisfy procedural requirements and respect fundamental limitations, including the prohibition on force and obligations arising from jus cogens.

For examinations, remember:

Article 22 → Countermeasure as circumstance precluding wrongfulness

Articles 49–54 → Detailed regime

Prior wrongful act → Target responsible State → Induce compliance → Proportionality → Article 50 limits → Termination

Gabčíkovo-Nagymaros → Leading case