Mark Tooley and John Keown have had an interesting exchange about whether the American Revolution was a just war. Tooley correctly argues that many people, especially on the religious left, employ Just War theory to effectively oppose any war. Some wars are definitely just (I would argue Afghanistan was such a war). But Just War theory is properly intended to restrain the use of force rather than to come up with elaborate justifications for its use.
That’s what those of us who subscribe to Just War theory find so troubling about the right’s recent embrace of preventive war. While preemptive wars can be just, it is difficult if not impossible for preventive wars to satisfy the criteria of Just War theory. Why? Because they tend to deal with speculative and hypothetical evils rather than actual, verifiable evils. In addition to muddying the concept of who is the aggressor, preventive wars cannot establish that the damage inflicted by the target is lasting, grave, and certain; it also becomes hard to establish that the evils resolved by the use of arms are in fact greater than those unleashed by the use of force.
Consider David Frum’s recent defense of the Iraq war in hindsight. Nearly every argument he makes for it is speculative. While some of his speculation is perfectly plausible and reasonable, the fact is we don’t know if he is right about all the evils he believes the war prevented or eliminated. We do know for sure what evils the war unleashed — massive sectarian violence in Iraq, ethnic cleansing, the persecution of Iraqi Christians, an increase in the Iranian government’s regional influence, not to mention the lives of thousands of brave Americans. Not everybody on the right believes Just War theory is adequate to deal with today’s security threats in an age of terrorism. But when the logic of preventive war seems to counsel more war, it might be worth revisiting.