Truly, our military actions can be highly destructive. To establish prospectively that a proposed military action would be just, we have the burden of proving, by clear and convincing evidence, that all of the core just war principles would be satisfied.

In the first part of this chapter, our shared responsibility for global human security is elucidated. For the sake of concreteness, a contemporary case is detailed: the case of Sudan versus South Sudan. In the second and third parts, the question of how the core just war principles are applied conjointly to particular cases is investigated. In applying them conjointly, two questions need to be distinguished. Would a proposed military action be just? Among alternative proposed military actions, each of which would be just, which one would be best? The former question is considered in the second part and the latter in the third part. Real-world moral judgements regarding particular cases can be complicated and controversial, when all things are considered.

I. OUR SHARED RESPONSIBILITY

According to the High-level Panel Report, the subtitle of which includes the phrase ‘our shared responsibility’, ‘the front-line actors in dealing with all the threats we face, new and old, continue to be individual sovereign States’ (HLPR 2004: 1).