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The Legal Significance of Unilateral Acts in relation to Disputes over Territorial Sovereignty

The British Institute of International and Comparative Law (BIICL) is delighted to embark on a new project on the legal significance of unilateral acts involving military or other use of force in relation to disputes over territorial sovereignty and related issues, especially when altering the territorial status quo in disputed areas.

This focus of this research is very timely. While the general prohibition on the use of force is uncontested as a general rule of public international law, the legal significance of unilateral military acts in relation to disputes over territorial sovereignty and related issues deserves greater examination in the light of recent global events. For example, the claim that Russian volunteers aided Russian rebels in Ukraine seems to fall outside the accepted definition of an armed attack, and the installation of a no-overflight zone over certain contested islands in the South China Sea does not by itself constitute a breach of the general prohibition of the use of force.

The project will also review military actions which by themselves do not constitute a threat but because they involve areas not permanently occupied, can have the effect of a change in status quo if others can no longer exercise their rights.

The primary focus of this research is the use of force to change the territorial status quo between States, in particular when a dispute exists regarding the territory in question. The aim is to deepen international discussion on the legality of diverse attempts involving the use of force to change the status quo in a disputed area. We specifically consider situations where military forces are deployed to effect such change (even if no casualties ensue) and situations where non-military use of force is applied with a similar purpose. Accordingly, the project will explore within and beyond the parameters of Article 2(3) and 2(4) of the United Nations Charter.

The project explores the dynamic and evolving parameters of what constitutes use of force in this area and also focusses on types of intervention which involve the use of the military. The project will thus also explore actions sometimes discussed as 'hybrid annexation'. In addressing these matters, this project considers other issues as they arise, including what constitutes a change to (or an attempt to change) the territorial status quo? In what contexts would the deployment of forces to disputed territories be justified under international law? What deployments might constitute an attempt to change the status quo (e.g. would the deployment of police forces as opposed to armed forces impact the legality of the action)? What other factors might affect the legality of the deployment of armed forces to a disputed area? What are the requirements and thresholds for constituting violations of Articles 2(3) and 2(4) of the UN Charter?

The research is a legal analysis of State practice and the determinations of international, regional and domestic courts. It will provide practical ideas of legal policy when it is published by June 2018.