What is one of the three principles of self-defense according to the Law of War?

Proportionality is a fundamental principle of self-defense in the context of the Law of War. This principle dictates that the response to an armed attack must be proportionate to the threat faced. In other words, any defensive action taken must not exceed what is necessary to repel the attack and must be scaled appropriately to the nature of the threat. This is essential to ensure that military responses do not lead to excessive harm to civilians or unnecessary destruction beyond what is required for defense.

Understanding proportionality helps maintain a moral and legal framework in military operations, ensuring that responses are measured and justifiable rather than retaliatory or overly aggressive. This principle is pivotal in international humanitarian law, which seeks to limit the effects of armed conflict and protect those who are not participating in hostilities.