The Concept of Proportionality in the Context of International Humanitarian Law and Its Customary Basis

This study decisively explores the principle of proportionality as an essential element of International Humanitarian Law (IHL), tracing its development from ancient moral codes to its formal codification in modern treaties and customary law. It effectively examines the critical balance between military necessity and humanitarian protection, illustrating how proportionality serves as both a legal standard and a moral guideline in armed conflict. By analyzing its historical trajectory from early civilizations and religious doctrines to medieval just war theory and contemporary international jurisprudence, this research asserts the enduring significance of proportionality. It underscores the principle's vital role in directing military decision-making to prevent excessive harm to civilians, its affirmation by international courts, and its integration into state practices and military manuals. The paper confidently advocates for a clearer and more explicit incorporation of proportionality in IHL instruments, calling for its prioritization by prominent international bodies such as the ICRC. Ultimately, this study positions proportionality not merely as a practical constraint on the conduct of hostilities, but as a profound embodiment of humanity within the laws of war.

本研究深入且严谨地探讨了作为国际人道主义法（International Humanitarian Law, IHL）核心构成要素的相称性原则，追溯其从古代道德规范到现代条约与习惯法正式编纂成文的发展历程。本研究切实剖析了军事必要性与人道主义保护之间的关键平衡关系，阐明了相称性原则在武装冲突中兼具法律标准与道德指引的双重属性。本研究通过分析该原则从早期文明与宗教教义、中世纪正义战争理论直至当代国际司法判例的历史演进脉络，论证了相称性原则经久不衰的重要意义。本研究着重强调了该原则在指导军事决策、避免对平民造成过度伤害方面的关键作用、国际法院对该原则的认可，以及该原则在各国实践与军事手册中的融入情况。本研究坚定倡导在国际人道主义法相关文书中更清晰、更明确地纳入相称性原则，并呼吁包括红十字国际委员会（International Committee of the Red Cross, ICRC）在内的重要国际机构将该原则置于优先地位。最终，本研究将相称性原则定位为不仅是对战事行动的务实约束，更是战争法中人性内核的深刻体现。