Countermeasures in International Law

Doctrine International Law Preferred

Otherwise unlawful measures taken by an injured State against a responsible State to induce it to comply.

Independent referenceNot an official or legal definition
Sources citedSee the sources at the end of this page
Status Under reviewLast updated 11 October 2026
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Definition

In plain language

If one State breaks international law against another, the injured State may in some cases respond with measures that would normally be unlawful, but only to push the wrongdoer to stop and make amends, and within strict limits.

Academic definition

The ILC Articles on State Responsibility (2001) treat countermeasures as a circumstance precluding wrongfulness (Article 22) and regulate them in Articles 49 to 54: they may only be taken against a responsible State to induce compliance, must be temporary and reversible where possible, and must be proportionate to the injury. Article 50 excludes the use of force, breaches of basic human rights, humanitarian law prohibitions and peremptory norms, and Article 52 requires the injured State first to call on the responsible State to comply and to notify its decision to take countermeasures. The ICJ applied similar conditions in the Gabčíkovo-Nagymaros Project case (1997) and rejected Hungary's reliance on them because the response was not proportionate.

Classification

Term type
Doctrine
Category
International Law
Subject field
International Responsibility
Subfield
Invocation of Responsibility
Difficulty level
Expert
Grammatical category
noun phrase

Language variants

Alternative terms
  • countermeasures
  • lawful countermeasures
Non-preferred terms
  • sanctions
  • reprisals
Abbreviations
  • not_applicable
Acronyms
  • not_applicable
Native terms
  • contre-mesures (French)
Transliteration
not_applicable
Pronunciation
not_applicable

Context

Legal effect: Binding

Scope

Covers lawful responses to an internationally wrongful act; retorsion, which involves lawful but unfriendly acts, and reprisals in armed conflict are separate, and UN Security Council sanctions are not countermeasures.

Legal context

ARSIWA Articles 22 and 49 to 54, widely seen as reflecting customary law in part, and the Air Services Agreement arbitration (1978) and Gabčíkovo-Nagymaros (1997). Article 54 leaves open whether non-injured States may take lawful measures in response to breaches of obligations owed to the international community.

Diplomatic context

States often label trade restrictions or asset freezes as countermeasures to justify them, and the legality of third-State countermeasures, for example against serious breaches, remains controversial.

Institutional context

Applied by the ICJ, arbitral tribunals and national courts, and addressed by the ILC in its commentary on the 2001 Articles.

Historical context

The doctrine evolved from the older law of reprisals, which was restricted when force was prohibited, and was codified in the ILC's 2001 Articles.

Why it matters

The rules separate lawful self-help from retaliation, so a State that goes beyond them may itself commit a wrongful act.

Usage

Register: Legal

Usage note

Use 'countermeasures' only for measures meeting ARSIWA conditions; other unfriendly acts are better called retorsion.

Example

State A suspended the treaty benefits as a countermeasure after State B failed to comply with the arbitral award.

Example scenario

State B violates a trade treaty with State A and ignores a request to comply. State A notifies State B, offers to negotiate, then temporarily suspends some of its own treaty duties in proportion to the injury, and restores them once State B complies.

Common misuse

Using 'countermeasures' to describe any retaliation, including sanctions imposed without a prior breach by the target State.

Not to be confused with

  • Retortion (retorsion)
  • Reprisal in armed conflict
  • Security Council sanctions
  • Necessity

Sources

  1. Articles on Responsibility of States for Internationally Wrongful Acts (2001), International Law Commission, Articles 22 and 49-54. legal.un.org
  2. Official definition. not_found_in_source
  3. Treaty reference. not_applicable
  4. Crawford, State Responsibility: The General Part. not_found_in_source
  5. ICJ, Gabcikovo-Nagymaros Project (Hungary/Slovakia), Judgment, I.C.J. Reports 1997. not_found_in_source

Source type: Institutional. Source reliability: Institutional.

This entry is an independent reference definition, not an official or legally binding text. Where an official definition exists, it is linked above and is authoritative. Read our methodology.

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