Next week a vastly important book will be published: "Preemption: A Knife That Cuts Both Ways" by Alan Dershowitz. Yes, that Alan Dershowitz: the very liberal civil libertarian, anti-capital punishment Harvard Law School professor. And but for my lack of his legal scholarship, there is nary a sentence in the book that I -- a very conservative editor of the Washington Times, and former press secretary to Newt Gingrich -- couldn't have written.

The premise of his book is that in this age of terror, there is a potential need for such devices as profiling, preventive detention, anticipatory mass inoculation, prior restraint of dangerous speech, targeted extrajudicial executions of terrorists and preemptive military action including full-scale preventive war.

In his own words, from his Introduction: "The shift from responding to past events to preventing future harms is part of one of the most significant but unnoticed trends in the world today. It challenges our traditional reliance on a model of human behavior that presupposes a rational person capable of being deterred by the threat of punishment. The classic theory of deterrence postulates a calculating evildoer who can evaluate the cost-benefits of proposed actions and will act -- and forbear from acting -- on the basis of these calculations. It also presupposes society's ability (and willingness) to withstand the blows we seek to deter and to use the visible punishment of those blows as threats capable of deterring future harms. These assumptions are now being widely questioned as the threat of weapons of mass destruction in the hands of suicide terrorists becomes more realistic and as our ability to deter such harms by classic rational cost-benefit threats and promises becomes less realistic."

Yet, such policies conflict with traditional concepts of civil liberties, human rights, criminal justice, national security, foreign policy and international law He shrewdly observes that historically, nations -- including democracies -- have resorted to such deviations from law and custom out of necessity. But that it has all been ad hoc, secret or deceptive. Prof. Dershowitz argues that now, rather, we need to begin to develop an honest jurisprudence of prevention to legally regulate such mechanisms. It is better, he argues, to democratically decide now, before the next disaster, this new jurisprudence -- the rules by which we will take these necessary actions.

To see the difference between traditional Anglo-American criminal jurisprudence and his proposed jurisprudence of prevention, he raises the great maxim of criminal law: better that ten guilty go free, than one innocent be wrongly convicted. That principle led our law to require proof beyond a reasonable doubt before conviction in criminal trials. Most of us agree with that standard.

But then Prof. Dershowitz updates the maxim thusly: "Is it better for ten possibly preventable terrorist attacks to occur than for one possibly innocent suspect to be preventively detained?" I would hunch that most people would not be willing to accept ten September 11th attacks (30,000 dead) in order to protect one innocent suspect from being locked up and questioned for a while.

Is it possible to go beyond such gut instincts and ad hoc decision making during a crises, and begin to develop a thoughtful set of standards for conduct in this dangerous new world? I don't know.

As Prof. Dershowitz observes, a jurisprudence develops slowly in response to generations, centuries of adjudicated events. But to the extent we recognize the need for it and start thinking systematically, to that extent we won't be completely hostage to the whim and discretion of a few men at moments of extreme stress.

At the minimum, an early effort at a jurisprudence of prevention would at least help in defining events. Consider the long and fruitless recent debate about the imminence of the danger from Saddam Hussein's Iraq, or the current debate on Iran's possible nuclear weapons. Under traditional international law standards they are both classic non-imminent threat situations: "early stage acquisition of weapons of mass destruction by a state presumed to be hostile."

But as Dershowitz points out, while the threat itself is not imminent, "the opportunity to prevent the threat will soon pass." Once they have the weapons it is too late. Continued...