This chapter critically approaches the principle of proportionality and tries to unveil its inhuman side. I begin with the Roman theological underpinnings to the principle of proportionality and then discuss its drafting history in order to explain how several delegates found the draft proportionality provision to be problematic. Thereafter, I discuss in detail the critical dimension of the proportionality principle with special reference to the wars on Ukraine and Gaza. I stress upon the vagueness in the provision and explain how the proportionality assessment is challenging for a commander. I reemphasize that certain effects of war, such as mental harm and reverberating effects do not factor in the assessment. I explain how the vague notion of military advantage may be abused by a powerful belligerent, especially on the ground of self-defense. I also argue that at times the principle may even encourage violence and justify death and destruction.