This video provides an in-depth look at the Principle of Proportionality, a key concept in IHL that seeks to balance military necessity with humanitarian concerns. It outlines the principle’s definition, its legal basis in Article 51(5)(b) of the Additional Protocol I to the Geneva Conventions, and its implications for military operations. The lecture discusses the criteria for assessing whether an attack is proportional, considering the anticipated military advantage against potential civilian harm. It also explores the intersection of proportionality with other IHL principles like distinction, precaution, and humanity, and examines case law to illustrate its application and challenges, including the issues raised by urban warfare and the use of autonomous weapons systems.