PARIS -- The first thing that must be said about the attacks in New York and Washington on Tuesday is that they have demonstrated the vulnerability of the United States, as of any modern society, to an intelligently prepared and determined attack.

Military officials and the uniformed and civilian analytic agencies attached to the U.S. defense establishment have for decades formulated speculative scenarios of attack on the nation, but their work has all but invariably been dominated by the high-technology mind-set of the Pentagon and by the engineering ethos of American society.

The planning has always suffered from the planners' assumption that their opponent would attack them in a manner symmetrical to the defenses they already had or that they planned to have.

Thus they concentrated speculation and planning on the danger of attack with mass-destruction weapons, probably using more or less high-technology methods. The discussion has almost entirely concerned missile attacks, rogue nuclear weapons and chemical and biological agents. Rogue commercial aircraft were not interesting to defense planners.

The real lesson, which was not learned, was provided nearly 60 years ago, shortly before the end of World War II, when an American medium bomber, lost in the fog, crashed into the Empire State Building in New York City -- then the country's highest building.

The lesson was that exotic methods and high technology are not necessary to produce devastating results. On Tuesday the lesson was validated. You merely need to crash three old-fashioned airplanes into vulnerable targets to produce mass panic in the United States, shutdown of most of the government and evacuation of the centers of Washington, New York and other major cities.

The second lesson was that the psychological and political consequences of such an event are not primarily measured by the scale of the casualties but by the unexpectedness and drama of the attack. So long as the attack remains anonymous, the fear and panic increase.

The effect sought is demonstration of the vulnerability of those who are targeted -- and the continuing vulnerability of those who might be targeted the next time. It is to demonstrate that high-technology defenses, of the kind in which the United States takes pride, can easily be circumvented, using simple methods. It is to demonstrate that there is no real defense against an anonymous attack that makes use of the ordinary functioning of civilian society.

Such an attack is possible so long as civil airplanes fly, trains run, power systems and utilities function, people go to work and business and markets continue. Each can be subverted, or intervened in, or exploited in ways that damage their users and the larger society.

Even a totalitarian security state cannot deal with this -- even if it were to suppress basic civil liberties. It is extremely important to understand this, since there will be two natural reactions to what has happened, both of them essentially futile.

First there will be continuing calls for revenge against whomever is responsible, presuming that the author is eventually identified.

The practical uselessness of revenge has repeatedly been demonstrated, and continues to be demonstrated in the Middle East, since those who employ terrorism are not functioning on a pragmatic scale of reward and punishment. As the Israelis find, making martyrs of your enemies invites further martyrdoms.

The second reaction will be that the United States needs even more elaborate defenses than now exist. Yet the Pentagon, CIA, NSA and the rest of the American apparatus of national security proved incapable of preventing the attacks Tuesday. They are incapable of preventing their repetition in some other version.

There are no technological defenses, as such, against this sort of thing. Surely, if nothing else comes out of the attacks Tuesday, they ought to have demonstrated to Americans the irrelevance of national missile defense.

There are ordinary security measures that can be taken or improved, but the nature of attacks mounted from within the regular functions of society, means that no comprehensive or conclusive defense exists. The entire history of terrorism in both 19th and 20th centuries has demonstrated that.

The final and most profound lesson of these events is one that it will be hardest for government to accept -- this government in particular. It is that the only real defense against external attack is serious, continuing and courageous effort to find political solutions for national and ideological conflicts that involve the United States.

The immediate conclusion nearly everyone has drawn about the origin of these attacks is that they come out of the Israeli-Palestinian struggle. It is reasonable to think that this is so, although there is as yet no proof.

For more than 30 years the United States has refused to make a genuinely impartial effort to find a resolution to that conflict. It has involved itself in the Middle East in a thousand ways, but has never accepted a responsibility for dealing impartially with the two sides -- locked in their shared agony and their mutual tragedy.

If current speculation about these bombings proves to be true, the United States has now been awarded its share in that Middle Eastern tragedy.

Los Angeles Times Syndicate.