This work sought to examine the epistemic implications of St. Thomas Aquinas’ just war theory on global peace. The intersection of war and peace is a recurring decimal in the history of philosophy. Hence, Thomas Aquinas’ just war theory emanates to address the ethical issue revolving around war and peace. This work makes use of analytic and critical methods. The work posits that Thomas Aquinas’ just war theory deals with the principle of jus ad bellum. Secondly, his just war theory (...) is intended or aimed at lasting peace which has connection with the postulation of jus in bello. Hence, Thomas Aquinas notion of lasting peace as the ultimate goal of war has to do with another important principle of just war theory—the jus post bellum. Finally, this work conceives that peace building or reconciliation ought to be extended beyond the confines of international or internal conflicts to promote global or international peace. Global peace is not a natural attainment rather it is something that needs to be constructed. There is the need for building and rebuilding of the global world on the principles of justice and peace by ending violence. (shrink)