Saint Augustine taught that warfare, while necessary on occasion, must always be guided by moral considerations--both as we deliberate whether to enter into a military campaign and as we actually engage in the conduct of military activity. This conviction that military campaigns are subject to moral guidelines needs to be proclaimed boldly in our own time.

The invasion of Iraq violated just war doctrine on at least two key points.

The use of violence in this situation was not our "last resort"--we refused to heed trustworthy voices that called for a continuing investigation of whether Iraq possessed weapons of mass destruction. And we failed to demonstrate that the risks we were taking in our invasion were proportionate to the ends we wanted to achieve.

One way to get your stubborn teenager to come out of his locked bedroom is to set the house on fire, but that would not be proportionate strategy. It seems clear now--and we should have anticipated this at the outset--that the invasion of Iraq would create a chaos that would be totally unmanageable.

I am not a pacifist. And I also believe that it is always a question of degree in our attempts to satisfy just war principles--World War II, for example, was fought for a just cause even though it failed to measure up to the standards of justice on several points.

But from a just war perspective, our engagement in Iraq was wrong-headed from the outset. The main question of justice now is: How do we act honorably in dealing with the mess for which we are responsible?