Another Just War or Just Another War?

What rationales do we use before we wage war? How can we justify it?

Actually, justifying war is the easy part.

Every nation or group that initiates violence believes that war is forced on it by the other side and so turn to just-war doctrine to explain the atrocities they are about to inflict on their fellow humans. 
--Kent Shifferd, 2011, p. 82

Shifferd is correct about the people of a nation or tribe or breakaway group--they are brought to the belief that not only is war justified, it is compelled by the corner into which another, unjust and violent, power has driven one's own peace-loving people. The most clearly aggressive wars are framed that way and people do not have the conscience, discipline and simple investigative motivation to challenge that frame.

What are the elements of this doctrine? From Wikipedia:

Criteria of Just War theoryJust War Theory has two sets of criteria. The first establishing jus ad bellum, the right to go to war; the second establishing jus in bello, right conduct within war.^[19]Jus ad bellumMain article: Jus ad bellumJust cause

• The reason for going to war needs to be just and cannot therefore be solely for recapturing things taken or punishing people who have done wrong; innocent life must be in imminent danger and intervention must be to protect life. A contemporary view of just cause was expressed in 1993 when the US Catholic Conference said: "Force may be used only to correct a grave, public evil, i.e., aggression or massive violation of the basic human rights of whole populations."

Comparative justice

• While there may be rights and wrongs on all sides of a conflict, to overcome the presumption against the use of force, the injustice suffered by one party must significantly outweigh that suffered by the other. Some theorists such as Brian Orend omit this term, seeing it as fertile ground for exploitation by bellicose regimes.

Competent authority

• Only duly constituted public authorities may wage war. "A just war must be initiated by a political authority within a political system that allows distinctions of justice. Dictatorships (e.g. Hitler's Regime) or deceptive military actions (e.g. the 1968 US bombing of Cambodia) are typically considered as violations of this criterion. The importance of this condition is key. Plainly, we cannot have a genuine process of judging a just war within a system that represses the process of genuine justice. A just war must be initiated by a political authority within a political system that allows distinctions of justice".^[20]

Right intention

• Force may be used only in a truly just cause and solely for that purpose—correcting a suffered wrong is considered a right intention, while material gain or maintaining economies is not.

Probability of success

• Arms may not be used in a futile cause or in a case where disproportionate measures are required to achieve success;

Last resort

• Force may be used only after all peaceful and viable alternatives have been seriously tried and exhausted or are clearly not practical. It may be clear that the other side is using negotiations as a delaying tactic and will not make meaningful concessions.

Proportionality

• The anticipated benefits of waging a war must be proportionate to its expected evils or harms. This principle is also known as the principle of macro-proportionality, so as to distinguish it from the jus in bello principle of proportionality.

In modern terms, just war is waged in terms of self-defense, or in defense of another (with sufficient evidence).
Jus in belloOnce war has begun, just war theory (Jus in bello) also directs how combatants are to act or should act:
Distinction

• Just war conduct should be governed by the principle of distinction. The acts of war should be directed towards enemy combatants, and not towards non-combatants caught in circumstances they did not create. The prohibited acts include bombing civilian residential areas that include no military targets and committing acts of terrorism or reprisal against civilians. Moreover, combatants are not permitted to target with violence enemy combatants who have surrendered or who have been captured or who are injured and not presenting an immediate lethal threat.

Proportionality

• Just war conduct should be governed by the principle of proportionality. An attack cannot be launched on a military objective in the knowledge that the incidental civilian injuries would be clearly excessive in relation to the anticipated military advantage (principle of proportionality).

Military necessity

• Just war conduct should be governed by the principle of minimum force. An attack or action must be intended to help in the military defeat of the enemy, it must be an attack on a military objective, and the harm caused to civilians or civilian property must be proportional and not excessive in relation to the concrete and direct military advantage anticipated. This principle is meant to limit excessive and unnecessary death and destruction.

Fair treatment of prisoners of war

• Enemy soldiers who surrendered or who are captured no longer pose a threat. It is therefore wrong to torture them or otherwise mistreat them.

No means malum in se

• Soldiers may not use weapons or other methods of warfare which are considered evil, such as mass rape, forcing soldiers to fight against their own side or using weapons whose effects cannot be controlled (e.g. nuclear weapons).

The paradox, of course, is that no proposed war can ever again meet the criteria because there is always a nonviolent alternative and last resort is never reached. Gene Sharp's list of 198 ways is old and out-of-date, but they should all be tried earnestly before waging war. Nonviolent actionists have invented many more since his 1973 list. It is virtually impossible to achieve last resort.

In truth, it is the leadership who generally has another agenda but slowly convinces the masses to go along with the war. The Just War doctrine is just a framing tool to provide plausible deniability, but the research into nonviolence is making that deniability less and less plausible every day.

References

Shifferd, Kent D. (2011). From war to peace: A guide to the next hundred years. Jefferson, NC: McFarland.