Just War as "Justice, Order, and Peace"

Reader Matthew Festa looks to an article on just war in a recent First Things, in which James Turner Johnson argues that

Of course, the sovereign has the right to authorize resort to the sword in defense against attack under way or immediately offered; even private persons have such a right. But Aquinas does not build up a conception of defense as just cause on the basis of the private right of self-defense; rather, he builds down from his overall conception of the sovereign’s responsibility for the good of the political community. Insofar as the need for defense provides just cause for public use of the sword, it comes from the responsibility of government to protect order, justice, and peace, not simply from the right to respond to an attacker in kind.

With this understanding in mind, Festa lays out the evidence:

We are working under the assumption that Saddam had no weapons but posed a significant threat to the US. Well, let's look what David Kay said ex post facto concluding that a) there were no WMD but that b) he posed a threat:

1. Saddam, at least as judged by those scientists and other insiders who worked in his military-industrial programs, had not given up his aspirations and intentions to continue to acquire weapons of mass destruction. Even those senior officials we have interviewed who claim no direct knowledge of any on-going prohibited activities readily acknowledge that Saddam intended to resume these programs whenever the external restrictions were removed. Several of these officials acknowledge receiving inquiries since 2000 from Saddam or his sons about how long it would take to either restart CW production or make available chemical weapons.

2. In the delivery systems area there were already well advanced, but undeclared, on-going activities that, if OIF had not intervened, would have resulted in the production of missiles with ranges at least up to 1000 km, well in excess of the UN permitted range of 150 km. These missile activities were supported by a serious clandestine procurement program about which we have much still to learn.

3. In the chemical and biological weapons area we have confidence that there were at a minimum clandestine on-going research and development activities that were embedded in the Iraqi Intelligence Service. While we have much yet to learn about the exact work programs and capabilities of these activities, it is already apparent that these undeclared activities would have at a minimum facilitated chemical and biological weapons activities and provided a technically trained cadre.

The man was a wacko with intentions to jump start his WMD programs again. Containing him impoverished the country and outraged Muslims. I do not think you could protect justice, order, and peace leaving this situation as it was. The man needed to go. . . .

So I guess it depends on what type of "just war" you're into. If you believe -- pace Johnson -- that the classical conception is better, then yes. If you believe[in] the enlightenment just war theory, then probably not.

It still seems to me that a just war conception constrained only by the broad terms of "justice, order and peace" is not much of a constraint at all.  We can't simply rely on the fact that Saddam was an evil force, can we?  The whole point of the just war tradition is to provide categorical limits on war so that we don't rely simply on our own conception of how much better off the world would be if we engaged in a particular war.  What are the categorical limits (not the Saddam-specific justifications) of this "justice, order and peace" just war tradition?

Rob