ALTHOUGH most Americans seem to understand the gravity of the situation that terrorism has put us in -- and the need for some serious military response, even if that means dangers to the lives of us all -- there are still those who insist on posturing, while on the edge of a volcano. In the forefront are college students who demand a "peaceful" response to an act of war. But there are others who are old enough to know better, who are still repeating the pacifist platitudes of the 1930s that contributed so much to bringing on World War II.

A former ambassador from the weak-kneed Carter administration says that we should look at the "root causes" behind the attacks on the World Trade Center and the Pentagon. We should understand the "alienation" and "sense of grievance" against us by various people in the Middle East.

It is astonishing to see the 1960s phrase "root causes" resurrected at this late date and in this context. It was precisely this kind of thinking, which sought the "root causes of crime" during that decade, creating soft policies toward criminals, which led to skyrocketing crime rates. Moreover, these soaring crime rates came right after a period when crime rates were lower than they had been in decades.

On the international scene, trying to assuage aggressors' feelings and look at the world from their point of view has had an even more catastrophic track record. A typical sample of this kind of thinking can be found in a speech to the British Parliament by Prime Minister Neville Chamberlain in 1938: "It has always seemed to me that in dealing with foreign countries we do not give ourselves a chance of success unless we try to understand their mentality, which is not always the same as our own, and it really is astonishing to contemplate how the identically same facts are regarded from two different angles."

Like our former ambassador from the Carter era, Chamberlain sought to "remove the causes of strife or war." He wanted "a general settlement of the grievances of the world without war." In other words, the British prime minister approached Hitler with the attitude of someone negotiating a labor contract, where each side gives a little and everything gets worked out in the end. What Chamberlain did not understand was that all his concessions simply led to new demands from Hitler -- and contempt for him by Hitler.

What Winston Churchill understood at the time, and Chamberlain did not, was that Hitler was driven by what Churchill called "currents of hatred so intense as to sear the souls of those who swim upon them." That was also what drove the men who drove the planes into the World Trade Center.

Pacifists of the 20th century had a lot of blood on their hands for weakening the Western democracies in the face of rising belligerence and military might in aggressor nations like Nazi Germany and imperial Japan. In Britain during the 1930s, Labor Party members of Parliament voted repeatedly against military spending, while Hitler built up the most powerful military machine in Europe. Students at leading British universities signed pledges to refuse to fight in the event of war.

All of this encouraged the Nazis and the Japanese toward war against countries that they knew had greater military potential than their own. Military potential only counts when there is the will to develop it and use it, and the fortitude to continue with a bloody war when it comes. This is what they did not believe the West had. And it was Western pacifists who led them to that belief.

Then as now, pacifism was a "statement" about one's ideals that paid little attention to actual consequences. At a Labor Party rally where Britain was being urged to disarm "as an example to others," economist Roy Harrod asked one of the pacifists: "You think our example will cause Hitler and Mussolini to disarm?"

The reply was: "Oh, Roy, have you lost all your idealism?" In other words, the issue was about making a "statement" -- that is, posturing on the edge of a volcano, with World War II threatening to erupt at any time. When disarmament advocate George Bernard Shaw was asked what Britons should do if the Nazis crossed the channel into Britain, the playwright replied, "Welcome them as tourists."