The Relationship between Third-party Countermeasures and the Security Council's Chapter vii Powers: Enforcing Obligations erga omnes in International Law

The article examines the relationship between third-party countermeasures and the Security Council's powers to adopt measures under Chapter vii of the United Nations Charter in response to breaches of obligations erga omnes. It is shown that the resort to third-party countermeasures is neither precluded nor subject to limitations as a result of the relationship to the Security Council's Chapter vii powers, even when both types of measures are adopted concurrently. Moreover, the fears that third-party countermeasures would interfere with or undermine the effective application of Security Council measures do not appear to have materialised in practice.