Last Wednesday morning, decorated war hero and current Secretary of State Colin Powell--a man who has fought in or helped lead his military in a half dozen more wars than all the politicians he now works for, combined--went before the United Nations and global television viewers and delivered what the Bush Administration has withheld for half a year: the firm evidence that it says justifies war.

Or not. Powell's lack of rhetorical grandstanding was welcome, as was the specificity of his charges. That being said, they still fail to justify launching a war.

The first and most obvious problem is that it wouldn't be a launch. It'd be a dramatic and gruesome escalation, to be sure, one that even its lead architect has compared, publicly and approvingly, to Hiroshima. But three presidents have been waging continuous war against Iraq's government and its people for a dozen years--from the Gulf War to economic sanctions to the unilaterally imposed no-fly zones to regular bombings to covert efforts to overthrow or assassinate Iraq's leaders to the current, steadily increasing bombing runs and psychological pressure on the Iraqis. Powell's presentation was not a case for war; it was part of the war itself, and should be understood as such.

The problem all along with a level-headed assessment of the Bush Administration's myriad justifications for an overt invasion and "regime change"--justifications that have been frequently shifting, at times contradictory, and often demonstrably false--is that they have been in the service of a predetermined conclusion. Regardless of whether a decision to invade had been made, and when, there's never been a question that Bush and his circle of hawks have wanted war, the bigger the better, and that the question in their minds was less whether it was justified than how to sell it to allies and to the public.

The White House's arguments for war all along have been less conclusions based on evidence than evidence based on conclusions--less like the determination of a judge, and more like the lawyers arguing to the jury. Powell's presentation to the UN, with its more concrete evidence and its more sober demeanor, should be considered every bit as critically, and skeptically, as those of the more hyperbolic prosecutors preceding him.

And, to quote the late, wondrous Peggy Lee: is that all there is? Powell's evidence rests primarily on two assertions: that Iraq's government cooperates with Al-Qaeda, and that it has also sought to hide evidence from UN weapons inspectors.

Assume, fancifully, that every word were true. It was the words not present that stand out. There is still absolutely no evidence that the Iraqi government, now or at any foreseeable point in the future, poses a security threat even to its immediate neighbors--let alone to the United States, halfway around the world. There is no evidence that Iraq, a country whose military is a fifth of its size ten years ago, a country crippled militarily (and in many other ways) by the most rigorous sanctions in world history, a country whose every move is closely monitored, a country which knows that any aggressive twitch would be instantly suicidal, now even possesses the capacity to inflict harm on any other country--let alone is threatening to do so, and let alone that the United States is among those threatened.

As a subset of those absent allegations, there is no evidence that Iraq possesses even any components of any weapons of mass destruction, let alone fully intact and operational weapons, let alone the means to deliver them outside its borders, let alone halfway around the world.

Powell didn't even try to make such a case; he argued solely that Iraq has repeatedly withheld from inspectors information of undetermined significance.

Even if true, this does not, legally speaking, justify an invasion; it simply permits that decision, in a legal sense. Under the resolution the US pushed through the Security Council last fall, failure to fully comply gives the United Nations the legal authority to authorize the use of force. It does not prove that war is necessary, or even that it is the best choice. It certainly does not give the United States carte blanche to do whatever the Bushies want.

Then there's Powell's Al-Qaeda claim. It would be laughable, were not the stakes so unlaughable. The United States wants to perpetrate Hiroshima-scale carnage, on the basis of one man sought on terrorism-related charges--a man whose links to Al-Qaeda are themselves tenuous--because he showed up briefly in Baghdad last year seeking medical treatment for a wound suffered in Afghanistan. It's nonsensical.

If Powell is stretching that far to make the case the Bush Administration has been desperate to make for 16 months--that Saddam Hussein had links to 9/11--it calls into question his entire presentation. Any objective reading of the legitimacy of Powell's case must include the question as to whether his "factual" evidence is, in fact, factual. One need not go back to the Gulf of Tonkin, or even the Kuwaiti incubator hoax before the Gulf War, to recall American governments lying to justify aggressive military policies. The Bush Administration has been misrepresenting facts on the ground routinely in its efforts over the last year to justify invasion; it has watched public support steadily erode despite those efforts. Our government has told us it would lie, to us and to the world, in service of its military goals. It risked a diplomatic uproar to seize the only, unread copy of Iraq's UN weapons report less than two months ago. It has had the tools, the time, and the motive to falsify evidence, and there is little or no corroboration for either Powell's satellite intelligence or his "human intelligence." It could all be true; it could also all be a cynical hoax. Nor need it be Bush's team that's doing the lying; that human intelligence is without question coming from people with much to gain by having the Americans put a government in power in Baghdad--a government likely to be run by Iraqis the Americans already know and have found helpful.

Ultimately, far too much of the Bush administration's case for war is undermined by its own eagerness--by the undisputed fact that their already-reached conclusion is driving both what they ask and what they hear. For opponents of an invasion, there is the same risk. Because the Bush command team is treating war as a first rather than a last resort, even very real threats posed by Baghdad risk being seen not as threats, but as justifications. Powell's testimony, by providing the evidence the Bush Administration has been so reluctant to divulge (understandably so, given its thinness), deserves careful and open-minded consideration. And there is the possibility, still, that further and far more damning evidence has yet to be divulged.

The decision to invade should not be taken as a six-year-old parses her or his parents' words, looking for the escape from bedtime. ("You said I had to go to bed. You didn't say I had to stay there!") A case for invasion should not rest on hair-splitting over the sins of Iraq, the wording of UN resolutions, or US claims of the right to unilateral invasions. It should be clear, compelling, and indisputable.

The onus is not on Iraq to prove a negative--that it would not and could not pose any sort of threat to the world or to the United States. It is instead Washington's responsibility to prove a positive: not only does a threat exist, but it is so grave and so immediate that it endangers the security of the United States, and that no other options exist but to invade. Moreover, each of those counts must be so overwhelming as to outweigh all the negatives of such an action: the enormous death toll likely, the monetary cost, the horrific global precedent, the risk of inflaming the world's most volatile region, the likelihood that it will provoke further terrorism against America, to name only five.

On all counts--the gravity and the immediacy of Iraq's purported threat to the US, and the lack of alternatives to invasion--Colin Powell made no such case Wednesday. It has yet to be made by anybody, inside or outside the Bush government. There is, as yet, no indication that such a case is even possible. Even as its soldiers mass at the borders, the United States is still a long, long way from showing that an invasion of Iraq would be anything other than an indefensible act of unprovoked war.