I was one of the American Catholics who publicly disagreed with the Vatican's contention that a war to disarm Iraq would not be just. On the whole, I still think war was right. But since we've failed, so far, to find Saddam Hussein's weapons of mass destruction, I feel obliged to address some questions — though not the most common ones at the moment (Saddam was definitely in Iraq at the start of the war, too, and we have not found him yet, either).

We need much better thinking on this war than we are getting at the moment. And it would be a good idea if we reflected deeply now, in relative calm, before we are faced with another decision about going to war.

Briefly, there's the frequent and false charges that the Bush administration deliberately misled the American people by distorting intelligence data. In the 1990s, Iraq's own government told the United Nations that it had about 2,000 gallons of anthrax and several tons of the nerve agent VX. U.N. weapons inspector Hans Blix reported to the Security Council early in 2003 that there was no “convincing evidence” that these weapons had been destroyed. In previous years, President Clinton, his CIA director, secretary of defense, Vice President Al Gore and even French President Jacques Chirac said essentially the same thing.

Germany, which opposed the Iraq war, published an intelligence assessment in 2001 warning that Iraq was close to building both nuclear weapons and missiles capable of reaching Europe. So even if the Bush administration chose to highlight data that supported its case, the case has widely been recognized as valid.

Like everyone else, I don't know what became of these weapons. I am certain that Saddam, who developed and held on to them despite a high international price, would not destroy them lightly — or without some benefit. But I do know what this means for the view that we should have given inspections more time: If American troops in full control of the country have had little success in finding these weapons, U.N. inspectors wrestling with an uncooperative government would never have found anything at all. This is a lesson to keep in mind not only about Iraq but also about similar situations in the future.

We have been slow to acknowledge this lesson, I think, because we are afraid to fully recognize the new nature of the threat weapons of mass destruction pose. My judgment about the Iraq war hinged on one basic fact: The just-war tradition needs to be developed in our time to deal with situations it has never faced before. St. Augustine or St. Thomas, both sharp observers, would have regarded the threat of weapons of mass destruction in the hands of people with a proven willingness to use them as alarming facts needing special and extensive treatment.

Many have argued — in line with past just-war thinking — that nothing should have been done in Iraq until that threat was imminent, that a vague threat does not justify “pre-emptive” warfare. But this approach does not really meet the new challenge. When all we had to worry about were conventional arms buildups and troop mobilizations, it took a lot before action became necessary. Now, inaction may be even more immoral than pre-emptive action. If we do not want to leave ourselves with some truly terrible all-or-nothing options, we need to start developing some new criteria now to help us sort out when going to war is “pre-emptive” and wrong, and when it might be prudential and right.

Such decisions might not be far off. Iran and North Korea, unlovely regimes whatever you think about how to deal with them, are openly developing nuclear programs. North Korea privately says it already has nuclear arms. Responsible secular and religious leaders need to review — now — what this might mean in the near future.

I was new to Washington in 1981 when the Israelis bombed the Osirak nuclear facility in Iraq. At the time, it seemed to me way beyond anything the just-war tradition allowed. I was wrong. If Saddam had had nuclear devices the past 20 years, the Middle East and the world would have been even far more terrifying. After Sept. 11, Gregg Easterbrook, a science writer with no particular taste for war, warned that if a terrorist nuclear device were to go off on American soil, “at least 300 million Muslims would die” in the response that would follow. All of us who care about peace and human well-being need to discuss all this creatively if we are to avoid such eventualities.

It would be a good idea to reflect before another decision to go to war.

So let me start the conversation by advancing some tentative theses in the hope that we will be better prepared for the decisions we will face:

1. Since we will not be able to tolerate developing weapons of mass destruction threats until they are beyond all remedy, we need to make clear where and when the line will be crossed.

Wherever they now are, Iraq's weapons were a threat to the Middle East and, like the Al Qaeda training camps in Afghanistan, inevitably would have become a threat to the United States as well. So we may do some useful thinking here: At what point does a developing threat need to be faced before it becomes, as it may already have in North Korea, weapons-of-mass-destruction blackmail? Do we need better intelligence confirmation of the threat than was the case in Iraq? But remember: No one, including the anti-war movement and the press, argued before the war that Saddam had no weapons of mass destruction. Facts and analysis will take us to a certain point; prudence and wisdom will ultimately have to decide.

2. Sanctions and inspections might play a role, but the use of force has to be a real option. We can debate both the place to draw the line and the standard of evidence that would allow the use of force. But the need to be able to do both is clear. In fact, the G8 countries meeting in Evian, France, in early June announced that they — France and Germany along with Britain and America — would not rule out a military response to nuclear proliferation. There are many tools that may be used first, but for Korea-like regimes one such tool has to be the threat of harsh, including military, consequences. Far from provoking wars, such policies might prevent them.

3. The use of force in these circumstances, even unilaterally, may be the most humane and selfless choice the world's sole superpower may make. Our deep desire for peace sadly cannot eliminate the need for war in present circumstances.

Modern Catholic social teaching encourages us to build up a world community that will replace the rule of force with the rule of law. But we are a long way from that system and the one we have has actually made things worse on occasion. Peace advocates will ask: Isn't there a less brutal way? Often, no. Catholic moral realism has to face that fact. We rightly worry about the easy resort to or excessive use of force. But in our world, we also need to worry about slow or inadequate response to threats.

Many Americans — I count myself among them — thought the first attempt on the World Trade Center the work of isolated fundamentalists. Those who warned us that this was just the tip of a worldwide terrorist iceberg seemed as fanatical as the people they were denouncing.

But after Sept. 11 we have to admit: They were right, we were wrong. Functionally, the United States, with its willingness to act and democratic mechanisms for assuring that its leaders do not act rashly, will be a better bet than any of the available international alternatives for the foreseeable future.

4. But that does not mean other paths cannot be found if people who take just-war theory seriously recognize their obligation not just to avoid wrong but to do right.

I have seen a deep reluctance on this point both here and in some European countries. It's easy to criticize America, but what is your answer to restraining evil in the world? There aren't many alternatives, unless you simply refuse real responsibility. Let's not forget that if the German Christian Democrats had won the elections last year, France would have been the only major country to oppose the Iraq war, and even it might have come around.

The people who will eventually have to fight and die if things go wrong also have the prerogative to make them go right. If others want to shoulder this responsibility, they are welcome to try. We will all be happy to help if we can, but in the meantime, show the same courtesy, okay?

Robert Royal is president,

of the Faith and Reason

Institute in Washington, D.C.