This seminal work by Ali Abdullah Fadlallah delves into the intricate concept of the 'Just War' within the framework of international humanitarian law and the law of armed conflicts. It meticulously examines the historical origins, philosophical underpinnings, and contemporary applications of jus ad bellum (the right to go to war) and jus in bello (conduct in war). Fadlallah critically analyzes how principles of necessity, proportionality, and discrimination are applied in modern warfare, addressing the challenges of defining and achieving justice amidst the complexities of armed conflict. This book offers valuable insights for scholars, legal practitioners, and anyone interested in the ethical and legal dimensions of war.