It is generally assumed that torture is impermissible, a throwback to a more brutal age. Enlightened societies reject it outright, and regimes suspected of using it risk the wrath of the United States.

I believe this attitude is unwise. There are situations in which torture is not merely permissible but morally mandatory. Moreover, these situations are moving from the realm of imagination to fact.

Death: Suppose a terrorist has hidden an atomic bomb on Manhattan Island which will detonate at noon on July 4 unless ... here follow the usual demands for money and release of his friends from jail. Suppose, further, that he is caught at 10 a.m on the fateful day, but preferring death to failure, won't disclose where the bomb is. What do we do? If we follow due process, wait for his lawyer, arraign him, millions of people will die. If the only way to save those lives is to subject the terrorist to the most excruciating possible pain, what grounds can there be for not doing so? I suggest there are none. In any case, I ask you to face the question with an open mind.

Torturing the terrorist is unconstitutional? Probably. But millions of lives surely outweigh constitutionality. Torture is barbaric? Mass murder is far more barbaric. Indeed, letting millions of innocents die in deference to one who flaunts his guilt is moral cowardice, an unwillingness to dirty one's hands. If you caught the terrorist, could you sleep nights knowing that millions died because you couldn't bring yourself to apply the electrodes?

Once you concede that torture is justified in extreme cases, you have admitted that the decision to use torture is a matter of balancing innocent lives against the means needed to save them. You must now face more realistic cases involving more modest numbers. Someone plants a bomb on a jumbo jet. I He alone can disarm it, and his demands cannot be met (or they can, we refuse to set a precedent by yielding to his threats). Surely we can, we must, do anything to the extortionist to save the passengers. How can we tell 300, or 100, or 10 people who never asked to be put in danger, "I'm sorry you'll have to die in agony, we just couldn't bring ourselves to . . . "

Here are the results of an informal poll about a third, hypothetical, case. Suppose a terrorist group kidnapped a newborn baby from a hospital. I asked four mothers if they would approve of torturing kidnappers if that were necessary to get their own newborns back. All said yes, the most "liberal" adding that she would like to administer it herself.

I am not advocating torture as punishment. Punishment is addressed to deeds irrevocably past. Rather, I am advocating torture as an acceptable measure for preventing future evils. So understood, it is far less objectionable than many extant punishments. Opponents of the death penalty, for example, are forever insisting that executing a murderer will not bring back his victim (as if the purpose of capital punishment were supposed to be resurrection, not deterrence or retribution). But torture, in the cases described, is intended not to bring anyone back but to keep innocents from being dispatched. The most powerful argument against using torture as a punishment or to secure confessions is that such practices disregard the rights of the individual. Well, if the individual is all that important, and he is, it is correspondingly important to protect the rights of individuals threatened by terrorists. If life is so valuable that it must never be taken, the lives of the innocents must be saved even at the price of hurting the one who endangers them.

Better precedents for torture are assassination and pre-emptive attack. No Allied leader would have flinched at assassinating Hitler, had that been possible. (The Allies did assassinate Heydrich.) Americans would be angered to learn that Roosevelt could have had Hitler killed in 1943, thereby shortening the war and saving millions of lives, but refused on moral grounds. Similarly, if nation A learns that nation B is about to launch an unprovoked attack, A has a right to save itself by destroying B's military capability first. In the same way, if the police can by torture save those who would otherwise die at the hands of kidnappers or terrorists, they must.

Idealism:There is an important difference between terrorists and their victims that should mute talk of the terrorists' "rights." The terrorist's victims are at risk unintentionally, not having asked to be endangered. But the terrorist knowingly initiated his actions. Unlike his victims, he volunteered for the risks of his deed. By threatening to kill for profit or idealism, he renounces civilized standards, and he can have no complaint if civilization tries to thwart him by whatever means necessary.

Just as torture is justified only to save lives (not extort confessions or incantations), it is justifiably administered only to those known to hold innocent lives in their hands. Ah, but how call the authorities ever be sure they have the right malefactor? Isn't there a danger of error and abuse? won't "WE" turn into "THEM?" Questions like these are disingenuous in a world in which terrorists proclaim themselves and perform for television. The name of their game is public recognition. After all, you can't very well intimidate a government into releasing your freedom fighters unless you announce that it is your group that has seized its embassy. "Clear guilt" is difficult to define, but when 40 million people see a group of masked gunmen seize an airplane on the evening news, there is not much question about who the perpetrators are. There will be hard cases where the situation is murkier. Nonetheless, a line demarcating the legitimate use of torture can be drawn. Torture only the obviously guilty, and only for the sake of saving innocents, and the line between "US" and "THEM" will remain clear.

There is little danger that the Western democracies will lose their way if they choose to inflict pain as one way of preserving order. Paralysis in the face of evil is the greater danger. Some day soon a terrorist will threaten tens of thousands of lives, and torture will be the only way to save them. We had better start thinking about this.