This thesis examines the ethical and legal legitimacy of Israel?s self defense claims and military operations in the 2023?2024 Gaza conflict through the analytical lenses of Just War Theory (JWT). In response to Hamas?s unprecedented assault on October 7, 2023, Israel invoked the right to self-defence under Article 51 of the UN Charter and launched extensive air and ground operations across Gaza. While these actions were framed as necessary for national security, the resulting humanitarian toll including the deaths of over 35,000 Palestinians by 2024, the majority of whom were civilians, and the destruction of critical infrastructure raised serious ethical and legal concerns. This qualitative case study draws on primary sources such as UN and NGO reports, government statements, and international media, as well as secondary academic literature on JWT and International humanitarian Law (IHL). The findings indicate that although Israel?s campaign fulfilled certain jus ad bellum criteria, such as just cause and legitimate authority, it failed to meet key jus in bello standards, particularly those concerning proportionality, discrimination, and necessity. From an IHL perspective, Israel?s repeated strikes on civilian structures such as hospitals, schools, and refugee camps violate the principles of distinction, proportionality, and precaution in attack, as codified in the Geneva Conventions. The study further highlights the ethical complexities posed by asymmetric warfare, where non-state actors like Hamas embed within civilian populations. Despite these challenges, the research concludes that Israel?s military response fell short of its moral and legal obligations under both JWT and IHL.