<p>The ethics of war involves a set of criteria that must be met for the use of force to be permissible, such as Success, Necessity, and Proportionality. However, the meaning of these just war conditions in relation to each other has not been sufficiently clarified. This study explores the structural distinction between the three just war conditions, by focusing on a triadic relationship among the dimensions of an action and its multiple consequences and by locating them in the Triadic Model. A key finding is that these conditions refer to different (factual and value) information for making a judgment, which underlies the need to separate their roles in justifying or constraining the use of force. Furthermore, to demonstrate the practicality of this model, this study briefly analyzes the recent war in Ukraine in terms of the three conditions. By assigning each condition a unique constraining role within a unified model, this study provides a consistent picture of assessing the overall moral permissibility of choosing a lesser-evil option.</p>