A year later, here's the question posed to those who argued that it would be morally justifiable to use armed force to compel Iraq's compliance with U.N. disarmament resolutions: if you knew then what you know now, would you have made the same call?

I would.

We know some things now that we also knew then. We know Saddam Hussein was in material breach of the "final" U.N. warning, Resolution 1441; his formal response to 1441 was a lie. We know he had the scientists, the laboratories, and the other necessary infrastructure for producing weapons of mass destruction [WMD]. We know he was seeking long-range ballistic missiles (again in defiance of the U.N.) to deliver biological, chemical, and perhaps nuclear weapons.

We know now, in even more horrifying detail, that Saddam's was a terror regime in which unimaginable brutality was normal state practice. We know, now as then, that Saddam's regime provided safe haven for terrorists.

And we should know now, as we should have known then, that these four facts --- Saddam's pursuit of WMD, his internal repression, his defiance of the U.N., and his links to international terrorism --- were of a piece. Some have said recently that Saddam himself was the real "weapon of mass destruction" in Iraq. That's a little too clever. But the truth in the trope is that Saddam's regime, as its actions and capabilities demonstrated, was an "aggression underway." The aggression took different forms at different moments over 20-some years. But the "aggression" was constant.

We also know now that we haven't found caches of WMD in Iraq. What difference does this make to the moral analysis?

Prior to the war, no one doubted that Saddam had WMD. The U.N. thought he did. France thought he did. The only question in dispute was, how was he to be disarmed? And while the investigation of Saddam's WMD programs is incomplete --- millions of pages of documents remain to be translated; some high-ranking Iraqi WMD scientists still refuse to cooperate --- it seems to me that something like this happened:

Saddam got rid of chemical and biological weapons in various ways: some were destroyed outright, other materials may have been sent to Syria, still other weapons may remain buried. Saddam was willing to bet that the U.N. would never authorize an armed enforcement of its resolutions; that the U.S. would cave in; and that he could then ramp-up his WMD programs after U.N. sanctions were lifted. Meanwhile, as David Kay noted in his now-famous report, internal controls were eroding in Baghdad, making it more likely that Iraqi military officers or scientists would transfer WMD to terrorists or other rogue states (which is why Dr. Kay told the Senate that, despite the failure to find WMD caches, Iraq was perhaps even more dangerous than we thought).

Suppose we knew all that in March 2003? Would that have made a substantive difference to the moral case for the war?

I don't think so. If the "regime factor" is crucial in calculating "just cause" in situations like this, the more complex WMD situation as we now understand it doesn't vitiate the case for the war. As David Kay suggested (in a largely unreported comment), it may strengthen it in some respects.

And while moral arguments from consequences are not without difficulties, the case for the war has also been strengthened by several of its results:

---Iraq is building the infrastructure of a civil society; no more mass graves are being dug; rape is no longer an instrument of state policy.

---A free press flourishes.

---Children are learning from reliable textbooks rather than being poisoned by propaganda.

---An interim constitution that provides protection for a broader array of human rights, and a more representative form of government than can be found anywhere else in the Middle East has been successfully negotiated by a wide variety of Iraqis.

---Iraq's economic resources, including its oil, are being used for the benefit of the Iraqi people, not a murderous regime.

---The Iraqi people are vigorously engaged in publicly debating their future, despite the efforts of terrorists to shut debate down.

A year later, I would still contend that the war was morally justified. The argument isn't a simple one. In this kind of world, it never is.

George Weigel is a senior fellow of the Ethics and Public Policy Center in Washington, D.C.