Some sort of U.S. military response to the terror attacks on the United States will soon begin. Only a true pacifist--someone who would not kill in self-defense-would urge inaction; true pacifists are rare. Since something's got to happen, the question becomes, what can America do without stooping to the tactics of the other side? Probably the nation will quickly find itself on the classic slippery slope from justified to questionable to wrong.

Surely air strikes can be justified so long as they are accurate and are specifically targeted at someone or something related to last week's events. There seems little doubt Osama bin Laden and Saddam Hussein have sponsored terror attacks against the helpless (both have links to the first, 1993 World Trade Center bombing) and there's growing indication that at least one of them had a hand in last week's horrors. This despite Bin Laden's weird statement of quasi-innocence, saying he hasn't sponsored any terrorism lately because the Taliban asked him to stop. This is little different from Henry Kissinger complaining that since he hasn't ordered the bombing of civilians in years, why do people keep pestering him about that?

If it became possible to target a cruise missile on bin Laden, Saddam or any of their immediate lieutenants, the argument for pressing the launch button would be strong, even knowing that there might be bystanders near and that there is a small chance the missile would go haywire and strike in the wrong place. Similarly, if U.S. planners had solid evidence of the location of terrorist training facilities, meeting places or similar targets, the argument for blowing these places up would be strong.

Morally, oddly, this causes us to root for the cruise missile and similar hi-tech "precision guided munitions," condemned as hi-tech nightmares. But in the last decade of use such weapons have rarely missed, and their accuracy allows warheads to be fairly small, limiting the risk of killing bystanders. (The fuel load of each jetliner that hit the World Trade Center had the explosive equivalent of about 1,000 tons of TNT; standard U.S. cruise missiles carry a half-ton warhead.) By the same logic, if planners knew where to find bin Laden or Saddam or similar figures the argument for dropping in commandos to capture or kill them would be strong, even though a bystander might be shot. Commandos may act secretive and stealthy, but so long as they are going after specific armed bad guys, there's no relationship between what they do and terrorists who strike the unarmed at random.

Using missiles or commando to get specific terrorists would represent the deliberate attempt to kill a named person--something U.S. forces have been prevented from doing since Jimmy Carter signed an anti-assassination directive a quarter century ago. Carter's directive was rooted half in his moral beliefs and half in the anti-CIA fervor of the mid 1970s, when congressional denunciations of spying were all the rage. (Sadly, it may be that the growth of the world terror network that struck last week was made possible by the de-toothing of the CIA, begun under Carter and not reversed by any subsequent president, including Ronald Reagan.

The notion that government leaders can act as judge, jury and executioner for foreign individuals is obviously unsettling. But there are instances where killing specific people may save much larger numbers. It would have been far more humane to target Saddam specifically during the Gulf War than to bomb Baghdad generally. Bush administration officials are about to rescind Carter's directive, which is an executive order, not a law, and thus may be altered at any time. If they can kill bin Laden or Saddam, this would be far preferable morally to any general military action.

The moral picture gets hazier when we don't know where the bad guys are--obviously, a problem when chasing terrorism. Bombing Kabul to coerce the Taliban into doing something about bin Laden would cause great suffering to the Afghan people, already reduced to near-Stone-Age existence by two decades of constant war, and by depredations imposed upon them by the Taliban.

Planners would try to pick Afghan military and infrastructure sites--U.S. forces have not deliberately bombed civilian areas since Kissinger's immoral Cambodian campaign, and then the tactic was widely opposed within the Pentagon. But at this point there are few left and none would have any direct link to the terrorism. We'd just be inflicting pain to see if it helps our position.

This haziness thickens considerably when the subject is Iraq.

If the United States attempted to bomb Saddam into abandoning terrorism, it would cause still more suffering for an Iraqi population that has lived for a decade in a country impoverished by the Gulf War bombs and Western sanctions, and rendered miserable by Saddam's tyranny.