Third-party countermeasures

Third-party countermeasures are otherwise unlawful measures taken by a state that is not an injured state within the relevant state-responsibility framework, in response to a breach protecting a collective interest. The ILC's 2001 Articles preserve the question of their availability. A state's right to invoke responsibility does not by itself settle its right to suspend a separate obligation. [1, Articles 48 and 54]

Legal structure

Article 42 defines an injured state. Article 48 allows another state to invoke responsibility where the breached obligation protects a collective interest of a group including that state, or is owed to the international community as a whole. Such a state may seek cessation and appropriate assurances, and performance of reparation in the interest of the injured state or the beneficiaries. Article 48 also imports the applicable notice, admissibility and loss-of-claim conditions. It does not give a non-injured state a claim to compensation for itself. [1, Article 48 and commentary 1-14; 2, Annex, Articles 42-48]

Article 54 preserves the ability to take lawful measures. Its commentary explains that the Commission deliberately left open whether states covered by Article 48 could take otherwise unlawful countermeasures. In 2001, it considered practice limited and uncertain. That historical assessment cannot establish the content of every later customary rule without examining subsequent practice and legal explanations. General Assembly Resolution 56/83 took note of the Articles and commended them to governments; it did not convert them into a treaty. [1, Article 54 commentary 3-7; 2, paragraph 3]

Distinguishing legal grounds

A restriction that is already consistent with the sender's obligations may be Retorsion. A third-party-countermeasure argument matters when the response would otherwise breach an obligation owed to the responsible state. Treaty suspension, an applicable treaty exception and action under the UN Charter are separate grounds that must be assessed on their own terms. The ILC commentary distinguishes measures by states from institutional action by international organisations. [1, Part Three, Chapter II commentary 3-4; Article 54 commentary 2 and 4]

The ordinary injured-state framework requires a compliance purpose, proportionality, protection of specified fundamental obligations and a route to resuming performance. It also includes notice, negotiation and termination conditions. Meeting those safeguards would not alone answer whether a non-injured state is entitled to rely on countermeasures in the first place. Countermeasures under the ILC Articles on State Responsibility (2001) sets out those separate conditions. [1, Articles 49-54]

Contemporary asset measures

The distinction matters for Sovereign immunity of central bank assets and Central-bank reserve immobilisation and confiscation. Temporary restrictions, use of revenues and an irreversible transfer of principal require separate legal analysis. Domestic authorisation cannot by itself establish international lawfulness. [1, Articles 49-55]

The UK-Ukraine Strategic Dialogue statement of 17 March 2026 provides a dated policy example. It recorded a commitment by the UK and wider G7 to keep Russian sovereign assets immobilised until Russia ceased its war of aggression and paid for the damage to Ukraine, and to consider lawful routes to funding. That statement establishes the stated policy and conditions. It does not, on its own, identify a complete third-party-countermeasure justification or establish customary agreement. No specific confiscation is treated here as lawful on that basis. [3, pillar one]

Evidence and safeguards

A claim about an emerging rule should identify the state, measure, breached primary obligation, standing under Article 48, separate obligation affected by the response and the state's expressed legal ground. Coalition size alone cannot supply those elements. The ILC's own historical examples show why action taken on another asserted basis should not automatically be counted as acceptance of third-party countermeasures. [1, Article 54 commentary 3-7]

Demands for cessation or reparation, notice, proportionality, review and termination conditions help assess a claimed countermeasure. They do not eliminate the threshold question of entitlement. This entry explains that legal distinction and a dated official policy example; it does not claim an exhaustive survey of post-2001 practice or a definitive ruling on the legality of reserve transfers. [1, Articles 49-54]

Sources

1. International Law Commission, *Draft Articles on Responsibility of States for Internationally Wrongful Acts, with Commentaries*, Yearbook of the International Law Commission 2001, vol. II, part two, Articles 48-55 and Part Three, Chapter II.
2. United Nations General Assembly, Resolution 56/83, *Responsibility of States for internationally wrongful acts*, adopted 12 December 2001, document issued 28 January 2002, paragraph 3 and Annex.
3. Prime Minister's Office, 10 Downing Street, and Ministry of Defence, *The UK-Ukraine Strategic Dialogue*, 17 March 2026, pillar one.