CROSS-BORDER TERRORISM AND THE ARMED ATTACK THRESHOLD: A DOCTRINAL ANALYSIS OF JUDICIAL INTERPRETATION AND STATE PRACTICE ON SELF-DEFENCE UNDER ARTICLE 51 OF THE UNITED NATIONS CHARTER
DOI:
https://doi.org/10.29121/ShodhSamajik.v3.i2.2026.155Keywords:
Armed Attack, Article 51, Armed Forces, Armed Groups, Armed Violence, Armed Use Of Force, International Law, Non-State Actors, State Responsibility, Terrorism, Self-DefenceAbstract
Cross-border terrorism has unsettled the state-centric assumptions on which the international law of self-defence was built. In the case of an armed attack, the United Nations Charter also reserves the right of individual and collective self-defence without providing definitions of what constitutes an armed attack or whether an armed attack by non-state actors from abroad satisfies the threshold. This paper examines whether, and under what conditions, cross-border terrorism qualifies as an armed attack, and evaluates the resulting scope of lawful self-defence. The study uses a doctrinal legal approach, examining the text of the Charter and the Articles on State Responsibility of the International Law Commission, the International Court of Justice's judgments in the Nicaragua, Oil Platforms, Wall and Armed Activities cases, the decisions of the Appeals Chamber in Tadić, the practice of the United States, Israel and India following the 2001, and principal academic commentaries. It is striking, however, that on the one hand there is the restricting approach of judges who require gravity and attribution by a state, and on the other hand, there is the expanding approach of the state which considers large-scale terrorist violence to be an armed attack, even if the proof of attribution is lacking, and which uses the unable-or-unwilling test and anticipatory self-defence. The paper concludes that this lack of consensus regarding thresholds of attribution, evidence and imminence allows for abuses to be made and that this undermines territorial sovereignty. It suggests the establishment of principles of attribution and evidence, greater accountability on a multilateral level, including the United Nations, and careful enforcement of necessity and proportionality to ensure that counter-terrorism remains within the boundaries of international law.
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