One of the criteria philosophers generally agree upon for just war is "legitimate authority"--that is, a just war must be authorized in legitimate (usually meaning lawful) ways. The United Nations charter and the U.S. Constitution, for example, set out procedures for properly authorizing war, as will the legal codes of most nations. To evaluate the legality of this war, one must extablish whether those procedures were followed in proper ways. In particular, here you should look at whether the U.S. Congress authorized the war and whether the U.N. Security Council authorized the war. (See Articles 39, 42, 51 of the UN Charter; also see Security Council Resolution 1441; see the U.S. Congress's Joint resolution on the war of October 2002.) Another issue to consider is whether or not, even if authorization was given, the authorization was rendered illegitimate or void since it was predicated on deceitful claims about the nature of the threat posed by Iraq. You may also consider whether any ...

I might add two bits to Oliver's remarks: 1. Democracies actually exhibit a rather militant history. 2. Wars of aggression, even if supported by a majority, would still, I think, violate important precepts of democracy. Democracy is not simply, after all, majority rule. It also involves protecting minorities and individuals (including the individuals of other nations) from the predation of the state and of majorities. A war of agreession civilly or internationally would violate these prinicples. Wars of self-defense or for the sake of protecting human rights are another matter.

I hesitate to make an absolute declaration, but for nearly all purposes the answer must be "no." They are simply too indiscriminate in their application, destroy disproportionally on too vast a scale, and cause too much suffering and too much environmental damage. There may well be, however, rare occasions when their use is warranted. In the case of bombing cities, I can't imagine a situation that would warrant their use, though that may say as much about my imagination as about nuclear weapons. With regard to Hiroshima and Nagasaki, besides the alternatives of conventional warfare and negotiated surrender, one might I think make a case for dropping the weapon over the sea or on an unpopulated land mass before using it on human populations.

Some philosophers don't justify war, holding that all war is immoral, either murder or something akin to murder. I am sympathetic with this view and believe that minimizing or ending war ought to be a goal we pursue. But until we get there, I recognize the importance of developing what philosophers call "just war theory." In just war theory, philosophers distinguish between questions about when it is proper to engage in war (questions "ad bellum") from questions concerned with the conduct of the war ("in bello") once engaged. As you suggest, ideas about both of these are ancient and may be found in the Greek, Abrahamic, and Asian traditions. Typically, however, historians of philosophy turn to Augustine of Hippo for the initial formalizing of the theory. Many have followed him in articulating important principles about just war, many of which have been codified into international and national laws. Here are some of the principles I regard as most important and most basic (note that some overlap a...