For Senator Clinton, reaching a decision on an American-led invasion of Iraq during the fall of 2002 involved a knotty set of calculations, some of which seemed preordained. If she voted yes, she would be giving President Bush the authority to launch a preemptive war — a concept that must have reminded her of America’s failed war in Vietnam, which she opposed as a student at Wellesley College and Yale Law School.
Once again, it must be noted that the Iraq war was not a preemptive war. It was a preventive war. I'll allow this Wikipedia entry to explain the difference fairly succinctly:
Preventive war is war launched in anticipation of a future loss of security or strategic advantage. Preventive war is sharply distinct from preemptive war, or anticipatory self-defense. Preventive war is only claimed to prevent a hypothetical attack which might occur in the future; for example, a war launched to prevent an adversary acquiring more powerful weapons. In international law, preventive war has no recognized status as distinct from a war of aggression. Many, if not most wars have been characterised as "preventive" in nature, often by both sides of the conflict.
The primary distinction is one of imminence of the threat. A preventive war is launched to remove a future potential threat. A preemptive war is launched to destroy a very real threat that is very likely to manifest itself as an attack on the preempting nation in the very near future. A nuclear strike on a country that you know is very close to launching a nuclear strike on you is a preemptive war. The Nazi invasion of Russia in 1941 was a preventive war. Preemptive war is recognized as legitimate under international law because international law recognizes the right of sovereign nations to defend themselves and does not require that those nations actually be attacked first (thus suffering a potentially devastating strategic setback) to do so. Preventive war is not recognized as different from a war of aggression because the threat is only hypothetical, and there is no real possibility of imminent attack. And, as you can well imagine, the threat of hypothetical future attack has been used to justify quite a few simple wars of aggression in the past, where the aggressor played up or hyped the threat of enemy attack to get his countrymen to sign on to an invasion. You know, kinda like we did with Iraq. I opposed the war in Iraq even though I was sure that Saddam Hussein possessed WMDs, because I knew (as would anyone who wasn't an idiot) that he was in no position to use them on us without suffering massive retaliation (and likely death) and even if he was considering using them, our response-invasion-was all out of proportion to the imminence of the threat. That's why the discussion over whether Iraq had WMDs is a red herring. Unless he had had WMDs pointed directly at us or our troops and was drawing up plans to use them or give them to terrorists to use on us, we were not justified in launching a full-scale invasion. There was never any evidence that he was, but our discourse on the war is still screwed up that nobody even seems to talk about that.
Anyway maybe you think I'm quibbling over technicalities of law, but I don't think you have to be a scholar of international law to recognize the difference. Four years into this gig, a journalist ought to know the difference as well.