“No event in American history is more misunderstood than the Vietnam War.” (Richard M. Nixon, 1985) Despite almost half a century of retrospect, numerous studies, and the declassification of military documents, former President Nixon’s assertion still holds truth. Of all the wars that the United States has fought in, the Vietnam War has compelled the most Americans to question what we were fighting for and why. Was the Vietnam War a just war?
The Just War Theory
The Just War Theory has been shaped over the centuries by historians and philosophers. However, the most systematic account of the Just War Theory was formulated by Saint Thomas Aquinas in his Summa Theologicae. According to the Just War Theory, the moral reality of war is divided into two parts. Wars are judged twice, first with reference to the reasons nations have for fighting and secondly, with reference to the means they adopt in the actual fighting. (Walzer, 21) The first judgment is referred to as jus ad bellum, or justice of war. The second judgment is referred to as jus in bello, or justice in war. Jus ad bellum provides guidelines for assessing whether a war is just or unjust while jus in bello outlines proper conduct in war. Jus ad bellum does not imply jus in bello. Likewise, jus in bello does not necessitate jus ad bellum. It is possible for a just war to be fought unjustly just as it is possible for an unjust war to be fought justly.
The principles of jus ad bellum are having a just cause, being declared by a proper authority, possessing the right intention, and having a reasonable chance of success. A war must meet all of these requirements to be regarded as a just war. The first and most important condition of jus ad bellum is having a just cause. This condition relies on what Saint Thomas Aquinas calls the Theory of Aggression. The Theory of Aggression can be summed up in six propositions:
1. There exists an international society of independent states.
2. This international society has a law that establishes the rights of its members—above all, the rights of territorial integrity and political sovereignty.
3. Any use of force or imminent threat of force by one state against the political sovereignty or territorial integrity of another constitutes aggression and is a criminal act.
4. Aggression justifies two kinds of violent response: a war of self-defense by the victim and a war of law enforcement by the victim and any other member of international society.
5. Nothing but aggression can justify war.
6. Once the aggressor state has been militarily repulsed, it can also be punished. (Walzer, 61)
From the Theory of Aggression it is clear that wars cannot be justly declared for political or religious beliefs, self interest, or aggrandizement. Only aggression towards the political sovereignty or territorial integrity of a nation can justify war. However, the tenet of self-defense can be interpreted to include preemptive strikes...