EXCERPT: Preventive intervention, though an old practice, has recently come under widespread discussion due to concerns about international terrorism and the potential availability to rogue states or terrorists of weapons of mass destruction (WMD). With the 2003 war in Iraq, the Bush administration made preventive intervention part of United States military policy. In a recent issue of Ethics & International Affairs
, Allen Buchanan and Robert Keohane argued
that the preventive use of military force may be justified in some circumstances. In this essay I take issue with their argument. A preventive use of military force, often referred to as a preventive intervention, is force designed to prevent an expected aggression--that is, an aggression expected to come sometime in the future from the target of the preventive attack. I will argue that any plausible moral justification for the preventive use of military force must show how the state that is the target of such an attack could be morally liable for attack when the aggression said to justify the attack is expected rather than actual. Buchanan and Keohane fail to provide such a justification.