The much anticipated Becker-Posner Blog has finally begun, with both authors taking on the issue of preventive war. Both make strong arguments, and I think their bottom line is clearly correct: we should not categorically oppose preventive wars. Sometimes the potential cost of waiting until the enemy has struck is so great as to justify taking preemptive action. (This theoretical justification is, of course, a far cry from justifying the specific actions taken against Iraq.)
Still, I was surprised to see Becker make (what I considered to be) two errors. First, he analogizes preventive war to punishment of attempted crimes (such as attempted murder): “Individuals can also be punished simply for planning or intending to commit crimes. … These arguments about intent apply much more strongly to preventive actions against terrorist organizations and rogue nations.” It’s incorrect to say the law punishes people for intent alone. The crime of attempted murder has two elements to be proven: (1) “specific intent” and (2) “an overt act toward commission -- this is intended to weed out the plotters from the perpetrators, but the standards vary widely by jurisdiction. Acts of preparation do not count” (source). Applying the analogy to preventive war, a hostile nation’s mere possession of armaments would not fit the bill, unless the armaments in question could serve no other purpose (such as defense). Note that in the case of Iraq, we didn’t even have proof of possession.
Second, Becker provides a faulty justification for the differential punishment of attempts: “The evidence required to punish intent has to be convincing, but the standard is weaker for violent crimes, like plotting murder, since punishment after the crime does not do anything for those murdered.” But the same could be said of punishing successful murderers: it does nothing for the murder victims. We do not regard that as an argument in favor of lowering the standard of evidence for murder relative to less violent crimes.
In general, criminal punishments do nothing for the victims except to make them feel that justice has been served. If you get raped, the rapist’s conviction will not make you whole. If you want compensation, you must take the rapist to civil court to get monetary damages. The only concrete sense in which criminal punishments help the victims is by causing there to be fewer of them, by deterring potential criminals from victimizing them to begin with.
I suspect the argument in Becker’s mind is something like this: “It’s good to punish attempted murder so we can prevent murders before they happen. And since murders are particularly heinous crimes, it’s particularly important to prevent them.” This argument is intuitive but spurious, because the punishment for successful murder also prevents murders before they happen. From the perspective of the potential murderer, any future punishment, including that for a successful murder, is a prospective cost of his choice.
The argument in favor of punishing attempted crimes, then, is in essence the same as the justification for punishing successful crimes: both create expected costs for potential criminals before they have committed their crimes, thereby enhancing deterrence. A reduction in the standard of proof, whether for successful or attempted murder, would increase the expected cost even more. But this argument in no way justifies a lower standard of proof for attempted murders as compared to other attempted crimes, unless it also justifies a lower standard of proof for successful murder as compared to other successful crimes. Perhaps we would be wise to adjust our standards of proof in that way, but I’m curious to know whether Becker would approve.