Five Rules Of A Just War
The Five Rules that must be followed for a war to be "Just"
Second Rule Of a Just War
There must a "just" cause or a good reason and a chance that the war can be won. An example of this would be to remove a tyrannical leader from a position of leadership. The removal of Saddam Hussein is one of these examples.
The Third Rule
War must be a last resort after all peaceful options have been eliminated and that war is unavoidable. An example of this is in WWII when the allied nations were unable to peacefully stop the Nazi advance in europe so the last option was to attack.
The Fourth Rule
The War must promote good and overcome evil. Peace and justice must be restored quickly. Again during WWII the allies wanted to remove Hitler from his leadership and stop his domination of Europe and later in the war to stop his mass exicutions.
The Fifth Rule
Proportionality- only enough force should be used as absolutely necessary to achieve peace. The innocent should be left alone in war. So far there haven't been wars where the innocent have been left and army haven't absolutely destroyed their opposition.