This scientific article provides a comprehensive analysis of one of the most acute contradictions in modern international law — the collision between a state’s right to self-defence and a people’s right to self-determination. The research traces the evolution of the right to self-defence from the classic “Caroline” precedent (1837), which established the criteria of necessity and proportionality, through the “Nicaragua” case (1986), which introduced a strict “effective control” criterion for attributing the actions of nonstate actors to a state, up to the contemporary Israeli-Palestinian conflict. The article argues that the prolonged Israeli occupation of the Palestinian territories, deemed illegal in the 2024 Advisory Opinion of the International Court of Justice, creates a legal paradox: an occupying power cannot legitimately invoke self-defence (Article 51 of the UN Charter) in a territory it itself controls. Simultaneously, the right of the Palestinian people to self-determination, repeatedly affirmed by UN resolutions, includes, under conditions of occupation, a right to resistance, which, however, must be exercised within the strict framework of international humanitarian law.

The key conclusion of the work is that resolving this fundamental duality and achieving a sustainable peace is only possible through the termination of the occupation and the full realization of the Palestinian people’s right to self-determination, which forms the foundation for genuine security for all parties to the conflict.