Due to the continuum of Hezbollah rocket attacks from southern Lebanon, Israel attacked Lebanon in July 2006, devastating infrastructure and causing substantial loss of Lebanese lives. This paper provides a detailed documented analysis that examines the applicability of Just-War concepts and criteria for the attack with a view to determine whether or not it was morally justified according to accepted international standards. After reviewing contemporary expositors, our analysis of Just-War criteria according to traditions stemming from St. Augustine and St Thomas Aquinas indicate that although a few criteria fit Just-War Theory, Israel had overwhelmingly failed to satisfy requisite conditions for both jus ad bellum and jus in bello, thereby rendering their Lebanon incursion unjustifiable, and therefore an unjust war.