Just War Theory can be found in almost all major cultures. But since war was a business that could not be easily stopped, some aimed to constrain it. In its classic form, Just War Theory has been around for several centuries—ever since nationhood in Europe replaced provincial governments. Having made some introductory considerations, I will ask: should Just War Theory be left as it is, changed, or, possibly, be completely abandoned? I will discuss the issue of the theory’s logicality first, and then move to the question of how technologies might force us to redo or abandon Just War Theory. Finally, I will discuss how changes in political life might prompt us to change the theory as we in the West have known it for several centuries.