Jus in bello:
St. Thomas Aquinas first laid out the Just War theory as:
1. Just Cause
2. Right Intention
3. Legitimate Authority
4. Formal Declaration of War
5. Reasonable Hope for Success
6. Last Resort
The problem with accepting Just War is that despite its logic and ethics it will immediately break down upon commencement. Creating ethics for war is like making a hammer out of porcelain: they both break on their first use. Niccolo Machiavelli illustrates in The Prince that morals and power do not mix. Connecting them is an impossible union. As Walzer says, “Inter arma silent leges: in a time of war the law is silent.” Take either Richard Wasserstorm statement that “morality has no place in war”  or General William Sherman’s famous quote “war is hell.”  In each case there is an understanding that, as Wasserstorm says, “war is the antithesis of law and rules.”  Anyone who has ever participated in play-fighting knows that the rules decided upon before play quickly deteriorate in almost equal proportion to the amount of injury inflicted upon each of the participants. The rules of any game are neglected when there is either the infliction of pain involved or when there is no referee to enforce them. The whole system of the Just War theory comes crashing down once war starts. The Coen brothers illuminate this point sarcastically when Walter announces to an opponent after his foot violation during a bowling game “this is not Nam. This is bowling. There are rules.”  Walter proceeds to draw a fire-arm at the protesting of his opponent and he screams: “has the whole world gone crazy? Am I the only one who gives a shit about the rules?” 
Walzer sums up the realist position saying: “what [is] conventionally [called] inhumanity is simple humanity under pressure.” Justice quickly changes from what is right to what it takes to get even with an enemy and it is skewed into the King Solomon view of “an eye for an eye; a tooth for a tooth”. Revenge overrides Aquinas’ two regulations for conduct in war: Non-combatant immunity and Proportionality.
Ethics are ignored in warfare because of fear. Things are seen differently when one is scared. Things quickly break down in the individual’s mind to a simple duality: their life or the enemy’s. Morals are negated in the effort to defeat the enemy and suddenly the, worst thing happens; ends are used to justify the means. Ironically, warfare is the means to peace; accordingly, each side will resort to any kind of violence if it means winning the war, ending the violence, on one’s own terms. This is why the statement “the war to end all wars” is a bigger oxymoron than the idea of a religious debate! Clausewitz argues in favor of Just War rationality stating that “means can never be separated from ends.” This union of ends and means justifies any action because it claims that any action was to avoid an even worse consequence. When Harry Truman dropped the first atomic bomb, it was with the intention of saving the lives of millions of Americans that would have been lost had the war with Japan continued. But this is exactly like the guessing game that has already been debunked; Truman could not possibly know what the outcome would have been had he not ordered the dropping of the bomb. There is no way to balance the means and ends so that the ends outweigh the means as some Just War theorists argue. Norman reiterates this point saying: “war cannot be justified simply by arguing that good consequences will outweigh the bad.” 
Another problem for the Just War theory is that it assumes that both sides will respect the rules. Quincy Wright’s definition of war is in much need of revision as he states that war “is a violent contact of distinct but similar entities.”  In most cases, wars are fought between nations that are quite distinct from one another. This difference could be the reason why the warfare started in the first place, as the two nations could not come to an agreement politically and thus resorted to violence. If one side fights with rules and the other does not, it puts the rule-abiding side at an obvious disadvantage. Historically, guerrilla warfare has been used in many victories: the Viet Cong over the Americans in Vietnam; the revolutionaries over the Batista government in Cuba; and, the Americans over the British in the American Revolution. The moral nation is forced from their just war theories to fight, as Ignatieff puts it, “terror with counterterror.”  Ignatieff states that this is the reason why so many “wars against terror degenerate into a downward spiral of violence.” Violence destroys all logic so that there is nothing left; no rules, no morals, no beliefs, just nihilism.
Bunny: Uli doesn’t care about anything. He’s a nihilist
Dude: Ah, that must be exhausting. 
A paper on The Big Lebowski would not be complete without some consideration of the nihilists and their threat to cut off the Dude’s “chonson.”  The nihilists demand ransom money after their kidnapping is proven to be a hoax. Walter explains to them that “without a hostage there is no ransom. That’s what ransom is.” In nihilism, there is no belief in rules so it is fitting that the nihilists would still demand ransom. What this scene shows clearly is how Walter’s vigilantism against the nihilist’s mugging turns for self-defense to a violent end in itself. Walter enjoyed defending his honor and taking a stand so much that when he fought the nihilists he was not just fighting a gang of muggers in self-defense but was fighting all his enemies and frustrations. He was fighting anti-Semites or Nazis, which he hates because of his devotion to his Jewish ex-wife and enemies of the American Army as he seemed to be having a Vietnam flashback during the fighting. It is not accidental that Donny dies while Walter is more concerned about his crusade than of protecting his friends. Walter loses himself in the combat when he viciously bites off the ear of Uli, the head nihilist. His ideals which he thought he was fighting for degenerate into nothing but violence. Like the nihilists, Walter has lost all his values. Ignatieff raises this paradox by asking: “how can a democracy resort to violence without destroying the values for which they stand?”  The answer is that it cannot. Vigilantism should be resisted at both the individual and international levels.
Jus post bellum:
In his book, War and International Justice: A Kantian Perspective, Brian Orend says that “Kant thinks that any purely domestic theory of justice…is radically incomplete.” Kant’s two reasons for why domestic justice fails on its own are, first, that reason is universal and, second, that a peaceful society will be vulnerable to external threats.  Kant’s domestic/international canon resembles more than just an airport; it resembles the home of the self/domestic canon as well. A peaceful person should be able to rely on domestic law enforcement to protect them and their peaceful way of life in the same way that countries should be able to rely on international law enforcement to secure international peace. Countries should be able to discontinue their international vigilantism and yet still be protected.
Norman writes that: “Notoriously, claims about human nature ascribe false universality to forms of behavior which are in fact culturally specific.”  Escaping subjectivity is always the battle of philosophers; only by consulting many viewpoints can one be said to be remotely objective. On the subject of human nature there are two main views. The first is optimistic: as both Hoffman and Fidler put it: “man is naturally peaceful and timid.”  They argue that humans are not violent by nature but that fear is what makes them resort to violence. If one could remove fear then, according to this view, one could remove violence. Elizabeth Anscombe is also optimistic when she argues, in her paper “War and Murder” that “someday… [humanity] shall do without [war and violence] and that the pacifist… tries to follow the ideal course, which future civilization must one day pursue.”  The second main view of human nature is pessimistic. Ceadel argues that “the cause of war [is man] himself.” The fact that Donny’s dies in the film demonstrates that unprotected pacifism is vulnerable. Krishnamurti argues that there can be “no escape from [violence]; nor must there be the exercise of will which says, “I will conquer it”– will is the very essence of violence.”  It is impossible to obliterate violence and very risky to try to contain it. Therefore the only option left is to channel it into other forms of behavior. Violence is just a form of energy, and with focus, it can be modified from destructive to constructive purposes. Krishnamurti states that:
the source of violence is the ‘me’, the ego, the self, which expresses itself in so many ways – in division, in trying to become or be somebody – which divides itself as the ‘me’ and the ‘not me’, as the unconscious and the conscious; the ‘me’ that identifies with the family or not with the family, with the community or not with the community and so on. It is like a stone dropped in a lake: the waves spread and spread, at the centre is the ‘me’. As long as the ‘me’ survives in any form, very subtly or grossly, there must be violence.
Humanity can only feel united for so long before the trance of togetherness is lifted and individualism breaks through. Since perpetual peace in togetherness cannot be obtained the goal must be to protect individuals from violent outbreaks.
Regardless of which view one may have of human nature, the construction of an international law and order can coincide with it. For the optimist, the idea is the utopia about which they have dreamt; for the pessimist, it would be the best protection for the individual in a violent world. The first step for the establishment of international law enforcement would be the construction of an international constitution  The construction of a world government would unite its nations the same way that a nation unites its provinces or states. It would diminish nationalism in the same way nationalism diminishes regionalism. This unity would help foster further diplomacy and thus foster peace. The key element needed in order to avoid the domination of regionalism and nationalism is full participation in the international constitution’s construction. All countries must feel a part of the constitution otherwise, as has been seen in Iraq’s resisting of democracy, they will revolt against it. Once the “law” is formulated then “order” needs to be established and enforced because, without “order,” “law” is neglected, and society’s structure is lost.
With a global police force, nations could pursue pacifism with comfort from this protection in the same way that individuals can pursue pacifism with comfort from local law and order. As a consequence of this protection, there would no longer be an argument to support the need for nuclear weapons as an offensive deterrence. 
The beginnings of such a world government for international law and order can be seen in the United Nations. But, just as the UN had to evolve from the League of Nations, a world government will have to evolve from the UN. Norman states that the UN is “an embryonic version of such an authority.”  If the UN is going to be an international government, it needs to be restructured to have both: (i) complete involvement of all nations, and (ii) a constitution written by all nations. Brian Flemming point out this need of reformation stating: “the UN turns 60 this year and badly needs a makeover.” In his article, “Reforming the United Nations,” he argues that the UN is overpowered at present by a few powerful countries, especially the United States. If the UN is going to have any credibility is must not be submissive to these powers. Recently it was seen that the United States could defy the UN with their pre-emptive strike against Iraq and face no consequences. The UN giving orders to the United States is like a group of toddlers giving orders to a fully grown, rambunctious bully. The first step may be to start from the drawing board, as the current structure may not be attractive to all countries. Some countries may be hesitant to join the “international” organization because the UN is based on an American style system of government.  Perhaps the UN could try another system of government, such a parliamentary government or the responsible government of the Westminster system. In a world-sized Hobbesian commonwealth, the big problem is how does the commonwealth get the biggest power in town to hop on the bandwagon without breaking it? The answer must be a slow process of assimilation of national to international systems. The UN needs a makeover but it will have to be patient; it may get face lift now, but it has to put the liposuction on layaway.