Whether and to what extent does international law allow states to use military force against armed non-state actors on the territory of another state?

Abstract

The relevance of the article is due to the importance of understanding the legal boundaries of state actions in the context of the growth of transnational terrorism, insurgent movements and asymmetric wars. Recent conflicts and military interventions highlight the urgent need to clarify international law regarding the acceptable use of force against armed non-state actors located in the territory of another state. Finding the delicate balance between respecting state sovereignty and ensuring the right to self-defence poses a significant challenge. The subject of the research is primarily the contemporary attribution concepts that may be used during the justification of the use of military force by states against armed non-state actors on the territory of another sovereign state. The purpose of the research is to critically examine legal aspects and state practice relating to the aforementioned concepts. The novelty of the study lies in the fact that by bringing together legal developments, state practice and some issues in using force sphere, the article offers new insights into the complex interralation between state sovereignty and the right to self-defence. Brief conclusions: 1) According to some states and experts, using military force against armed non-state actors on the territory of another state violates the sovereignty of that state, whereas others claim that it may be justified under the right of self-defence. In this regard, state practices have been inconsistent. 2) Nowadays, the «effective control» test is the only legally justified approach that triggers the right to self-defence against armed non-state actors on foreign soil. 3) There is no well-established state practice and opinio juris relating to other examinded attribution tests or the «Unable or Unwilling» doctrine.