This Article addresses the reliance of both policymakers and scholars on just war theory as a guide to twenty-first century war. More especially, it evaluates the assumption that the UN Charter system is a modernized form of historical just war theory. The Article traces the genesis of various just war theories from ancient Greece and Rome through medieval Christianity, arguing that these theories were based on moral and religious obligation. In the early modern era, as papal supremacy weakened, just war theorizing tended to wane. In its place, four different approaches to limiting war began to emerge: public international law, jus in bello, reason of state, and balance of power. Although there are indications of a revival of just war thinking in the twentieth centuU, the Article argues that it is a fundamental mistake to understand and treat the UN Charter as an adaptation of traditional just war principles. Instead, the UN Charter expresses an overriding commitment, not to the aim of ensuring that war is waged if and only if it is just, but rather to preserving the existing international order, regardless of that order's justice or injustice. The UN Charter forbids both preventive war and humanitarian intervention unless authorized by the Security Council. International justice and the promotion of peace would be far better served, however, by a more flexible approach than is afforded either by historical just war theory or by the Charter system.
Delahunty, Robert J. and Yoo, John
"From Just War to False Peace,"
Chicago Journal of International Law:
1, Article 3.
Available at: https://chicagounbound.uchicago.edu/cjil/vol13/iss1/3