The principle of proportionality in attack is a cornerstone of international humanitarian law (IHL) and the law of armed conflict, aimed at balancing military necessity with humanitarian considerations. Its evolution has been shaped by centuries of warfare, legal codification, technological advancements, and ethical debates. At its core, proportionality seeks to limit excessive harm to civilians and civilian objects relative to the anticipated military advantage of an attack. However, its application and interpretation have remained a subject of debate, both legally and practically, particularly in modern conflicts characterized by asymmetry, urban warfare, and advanced weaponry. Historically, the roots of proportionality can be traced to early codifications of the laws of war, such as the writings of Hugo Grotius in the 17th century, who emphasized restraint and the protection of non-combatants. Grotius and subsequent thinkers laid the ethical and legal foundations for proportionality, arguing that military actions should be guided not solely by effectiveness but also by moral responsibility. However, early warfare was largely conducted in conventional settings, where distinguishing between combatants and civilians was relatively straightforward. Proportionality in this context primarily concerned limiting unnecessary suffering and avoiding wanton destruction beyond immediate military objectives. The formal codification of proportionality in the modern era took shape through the Hague Conventions of 1899 and 1907 and, more comprehensively, in the Geneva Conventions of 1949 and their Additional Protocols.