The theory of just war goes back to the fourth century theologian Augustine. The theory is rooted in the belief that while Jesus taught and practiced non-violence, the presence of evil in the world sometimes makes violence a sad necessity. The tenets of Just War Theory were developed to help state leaders carefully evaluate the circumstances before going to war.
War has always been a brutal business with innocent people frequently caught in the crossfire. The development of modern mechanized war has made the brutality even greater and the suffering of innocents even more widespread. In short, the need for careful reflection before waging war is more critical now than ever before.
Though modified over time, the basic criteria for determining if a war is just are as follows:
First, there must be a just cause. Historically, the most obvious just cause has been self defense after being attacked. However, just war theory also allows for defending a weaker state from the aggression of a stronger one.
Second, there must be right intent. A state must fight the war because of the just cause, not for some other reason. Using a trumped-up cause as a way to seize the natural resources of another country would be an example of wrong intent. Revenge or seeking to inflict pain for pain's sake would also be examples of wrong intent.
The third tenet of Just War Theory is proper authority and public declaration. The main idea here is to prevent rogue elements of a state from waging war. In the United States, only Congress can declare war, though changes in the role of the president in recent years have blurred that understanding considerably.
The fourth tenet of a just war is that war should always be the last resort. In order for a war to be just, every other means of settling a dispute must be exhausted. This tenet of Just War Theory seriously calls into question the recent practice of "pre-emptive war."
The fifth tenet is a high probability of success. This is Parham's concern about our current war efforts in Afghanistan. Will the suffering and displacement caused by additional troops and the expansion of the war make things better or worse? The cost of war is too high to be waged without the hope of a significant positive outcome.
The final criterion of Just War Theory is proportionality. Even if the goals can be successfully met, are they worth the effort? Will the evil inflicted by the war be more or less than whatever good comes from the conflict?
These are profound ideas, hashed out over time by some of the most faithful followers of Jesus' teaching. These ideals now transcend all faith traditions and exist as the basis of international law. Sadly, in recent years, political leaders in our country have only given lip service to these ideals. If we aspire to be a Christian nation, as many claim we are, or even if we simply desire to live as moral people, then we must be sure that the wars we wage are based on a just cause.