War is wrong unless it's the last resort to solving an important issue. The best ways of rationalizing war are self-defense and for a cause such as stopping a crime against humanity. An example of the first rationale, self-defense, is Belgium fighting the German Empire in World War I in order to not lose land, sovereignty, and other things. An example of the second rationale is when the U.S. and other Allies invaded Nazi Germany-occupied Europe in order to free the countries and peoples whose lands and lives were being ravaged by the Germans, plus to stop the increasing amount of deaths from the Holocaust, a crime against humanity done by the Germans. These are the two most-reasonable rationales for creating war.
In comparison between the two ideologies on which is better to view the subject of war, the most practical one for modern times, and possibly for the past too, is consequentialism. This is because many actions could be inherently or by default “bad” but could be justified because of their outcome or the context in which they occurred. An example of this would be if someone ran over a person on the highway. This is immediately viewed negatively because it involves taking a life. However, if not hitting the person meant swerving into a truck carrying a tank of gasoline, causing that truck to crash and explode on the highway, then the former option would be the optimal scenario. In war, this type of choice must be made often. Oftentimes, the wrong outcome occurs, even if a just outcome was intended. Leaders may not know everything about the places they attack and that leads them into trouble.
I agree with McMahan’s idea that we can’t make soldiers think that they have permission to do immoral things while serving, even if those actions are accompanied by good manners and respect. This is because a lot of times people will be swept up in the crowd and whatever the crowd does. This ties in to mob mentality. This is the notion that peoples’ bad behavior, decisions, and actions are all magnified in large groups. This has occurred many times throughout the world. Groups often unify under one person, then when that person takes responsibility for the wrongdoings, that person’s followers are more than happy to carry out the deed.
I don’t believe Jus Ad Bellum stops unjust wars from happening but it does encourage better behavior and ethics during war. This is because many countries will follow the guidelines of Just War Theory, but their soldiers on the ground may do wrong things that are against the rules. This then leads to trials of course. “Just war theory deals with the justification of how and why wars are fought” (excerpt 1). Without this, nations would have zero desire to be good to each other during wars, and there’d be problems similar to those in the First World War that would occur on the battlefield. This is the extent of the effect of Just War Theory.