The direct use of force is such a poor solution to any problem, it is generally employed only by small children and large nations. ~David Friedman

Why do we do it?
1. Wars of aggression. We want other people's stuff or land, so we take it, if we can.
2. Defensive war. Someone is trying to take our stuff or land, & we fight them over it.
3. Righteous war. We provide protection or aid to a friend, or to rid the world of evil. Slogans like, 'Make the world safe for democracy', or 'The war to end all wars' are used to rally people.
4. Preemptive war. The idea that to promote peace, we need to invade or bomb another country to prevent war.
5. Wars of manipulation. This is when propaganda or deception is used to manipulate people to believe that war is the only recourse in dealing with a problem. A scapegoat is created, blaming the nations' problems on them. It can be someone internal to the nation, like jews, the monarchy, the capitalists, the bourgeois; or it can be something outside, like infidels, the suffering children, or the Great Satan.
6. Wars of destiny. We have been chosen by a higher power or ideology to subjugate other nations, for their own good. It is our duty to promote our ideology with them, & help them, even if we have to kill them. These sometimes have religious tones to them, calling upon god to help us slay the wicked & promote his righteousness. People are called to sacrifice altruistically for the cause, or to god, or for the betterment of mankind.

Some of these reasons overlap, & build upon each other.
Usually, war is not something that is done logically. It is an emotional appeal by the leaders. People naturally get fired up over war.. it appeals to the nationalistic fervor of the citizens, & leaders often use the distraction of war to solidify their power base if it starts to weaken. But it is the very quality of the emotional appeal of war that makes it difficult to manage. It is more like a forest fire than a controlled burn. Things can quickly escalate until the whole world is in the throes of war.

War, in it's most basic form, is the ultimate extension of morality. Might makes right. Those who win the wars, write the history. They always show justification for their actions. There is no problem that cannot be solved by war. Any question of ownership, sovereignty over land or sea, racial or ethnic superiority, or any other issue that comes up in inter human relationships can always be settled with violence.

What should be the attitude of a free people, regarding war?
1. Be honest. Of course, we won't do that; neither will the promoters of war. They always use justification.. emotionally based calls for the rightness of the cause. We won't just say we want the other guy's stuff, it has to be a noble cause for justice & liberty. But if we were honest in our true motivations for war, we would eliminate a lot of suffering & needless destruction.
2. Live & let live. We don't have to take it upon ourselves to dictate to other nations how they should live. A free society should be tolerant within AND without. But we won't do that, either. We're a meddlesome, bossy species, always involved in other people's business.
3. Speak softly & carry a big stick. Any aggressive force can be met with an equally ferocious force. We do not have to be peaceniks or quakers, but can defend ourselves.
4. Be skeptical of the manipulators. Something this serious should not be entered into with whimsical emotions. We should have clear, well defined boundaries for any military action. If they want to make the argument that we need to invade another country & take their stuff, they should make that case. But we should not be manipulated with images of crying children or tales of injustice.
5. The military should not be the decision makers for war. They exist for war, & always have a solution ready, based on violence, destruction or intimidation. They should be the implementers, if war is chosen.

The US constitution has clear boundaries for entering into war. But the leaders have bypassed the constitution (ignored it) by using emotional appeals. 'We need to save the children!' 'These people are evil & need to be defeated!' But the central question should not be, 'What can we do to end this injustice!?!' It should be resolved with #6 above.. Is it our duty or destiny to provide justice for the world? THAT is the central motive for most of the wars in the last 100 years. America has felt an obligation to be the global justice provider. It is an extension of 'manifest destiny' of imperialistic times, & needs to be directly faced. It is not a valid reason to use violence on other nations, if we no longer believe in the basic ideology of global destiny.

Here's why the US should NOT be involved in other nations' affairs, or be 'the policeman of the world'.
1. We cannot afford it. It is that simple, & that should be enough. If we had a balanced budget, we would not do it. The taxpayers would revolt over oppressive taxation. But the politicians do it anyway, & send our children the bill.
2. To be consistent, we would have to show moral outrage over EVERY injustice on the planet, & bomb nations in africa, europe, asia, south america, & mexico. Instead, we hypocritically pick & choose where we want to fight injustice, turning a blind eye to other places.
3. Propping up evil dictators is unbecoming for a free people, as is promoting any corporate interests, or supporting crony corruption.
4. It is possible to be a neutral, freedom loving nation. We can be like switzerland.. which the left always gazes at with longing & adoration. Why not adopt their foreign policy?
5. We cannot trust bureaucrats or military intelligence to provide a full picture. There is always a hidden agenda, or propaganda, or some manipulation going on. Military actions should be clear matters of national security, not emotionally based fear mongering.
6. We make enemies of people we could be at peace with. Our meddling feeds the 'ugly american' syndrome.
7. Innocent blood is on our hands. We are responsible for the deaths of innocent people.. collateral damage. Our own soldiers are sacrificed for some politician's dreams of glory or historical significance. We the people should not be dupes to their manipulating propaganda.

Most people will read this (long!) treatise about war & agree. They see the rationale & the evils of war. But as soon as there is some hyped up event, all the basis for our actions are forgotten, & the hysteria of war seizes the discussion. We are too easily manipulated by some politician's agenda. Emotion rules, rather than a solid philosophical basis. We need to get our ideological ducks in a row, & keep them there, especially in times of hysterical shouts for war.