But I never really had a handle on the psychology of this movement until this week. Now, reading letters to the newspapers, listening to the phone- ins, absorbing the arguments of historians such as Correlli Barnett, studying the speeches of politicians such as Alex Salmond, Tony Benn and Alan Clark, I think I can see how it happened. I comprehend how basically decent people can use every argument at their disposal to seek to avoid confronting something that they know (or ought to know) is intolerable.
And when you examine the views of the man and woman on the Belgrade tram, it is easier to see how so many Germans in the Thirties bought the Joseph Goebbels version of the world.
As a 1992 study showed, even when offered sources of information independent of the government - and despite believing these sources to be more accurate and truthful - most Serbs preferred to stick with the xenophobic official newspapers and broadcasters. They were comforted by the easy fix of the propaganda, and disconcerted by the truth.
Yesterday, the BBC's John Simpson, who had previously been at pains to note how uniform support for Milosevic had been (and thus, by implication, how unsuccessful the bombing was), reported from Belgrade on the way that Serbs were dealing with the reports of what their sons were doing in Kosovo.
"They don't want to know about it, frankly," he said. In other words, their allegiance isn't up for grabs; they cannot see why their country should be bombed because they do not want to see why it should be bombed. And we could wait till hell freezes over before Serb public opinion helps to stop the slaughter in Kosovo.
The fact that ordinary Serbs are convinced by the nationalist, racist and paranoid rhetoric of their own media and government is a strange reason for holding back on Nato action to save the Kosovar Albanians. Nevertheless it is one among many ingenious arguments thrown against the action by those who oppose it.
The other favourite one - now being flogged for all it's worth - is that the Nato bombing has provoked the current attempt by the Serbs to "ethnically cleanse" the entire province of Kosovo. This, it seems to me, is a bit like placing the blame for the Holocaust on the Allies, on the basis that there were no death camps before we declared war on Germany. One day, in some Belgrade archive, or inside a buried box, we shall discover the plans for the "cleansing" of Kosovo, drawn up long before last Wednesday.
On Monday night, with the refugees streaming into Macedonia and Albania, Alex Salmond, leader of the Scottish Nationalist Party, denounced the Nato military action. It was, he said in a television broadcast, "unpardonable folly", an action of "dubious legality". He was also against putting in ground troops.
"Sometimes the right thing to do," he went on, "is to negotiate patiently even with those we find repellent, to recognise that economic influence is more effective than military might, and to accept the moral strength of relying on international law, even when it seems frustrating or ineffective."
Note the "sometimes" there. It suggests that, just as often, it is right to take up arms against those who are morally repellent; that "sometimes" it is also right to use military force; and that "sometimes" a legalistic regard for international law can become an excuse for inactivity. And God alone knows that, if this is Mr Salmond's opinion, and he is not simply a pacifist, then Kosovo is the "sometimes" when intervention is justified.
Can it really be, I wonder, just four years since lightly armed Dutch UN troops watched helplessly as thousands of men were taken from their families in the UN "safe haven" of Srebrenica?
The Bosnian men were driven by bus to a large field where they were shot and buried, and the testimony of the survivors is exactly the same as that of survivors of Einsatzgruppe mass executions in Nazi-occupied Eastern Europe. Surely to God, Alex, we haven't forgotten already?
If the West does indeed share some blame for Srebrenica, it is not because it used too much military force, or that it intervened too soon. It won't be because it had insufficient regard for international law, or because it refused to deal with people we regarded as "morally repellent". It was because it was weak, disunited, lacking in determination and hopelessly, absurdly optimistic about the "realism" of men such as Slobodan Milosevic.
The Benns, the Salmonds, the Healeys, the Clarks, the Tapsells, the people who write letters to this paper splenetically blaming their own government for the current situation while absolving the Serbs, are all to be commended for expressing their views. It is not their fault that Slobodan Milosevic and his propaganda machine use every such utterance to convince themselves and the Serbian population that Nato is split and will soon give up. Hopefully, the Serb regime will soon be disabused.
The isolationists, the nostalgic anti-imperialists (so well described in these pages yesterday by Ken Livingstone), the Tories who now seem to believe that there is no such thing as international society, the inveterate opposers of all things, must secretly pray that no one over here takes any notice of them. Can they possibly imagine what would happen now, were Nato to give up and go home?
A former American ambassador to Yugoslavia, Warren Zimmerman, once coined the phrase, "the paradox of prevention". The paradox is that democratic states cannot be easily mobilised to take action to prevent something happening, because - by definition - it hasn't happened yet.
Until Srebrenica, I was one of those who carped at the idea of Western ground troops being deployed in large numbers to enforce a peace. I was wrong.
I don't really want to be wrong like that again. It is now clear that there can be no Kosovar autonomy within a Yugoslav state, and that the actions of Serb thugs and murderers have rendered the provisions of the Rambouillet agreement inoperable. Some kind of Kosovar entity will have to be reconquered, protected and assisted. This will require ground troops, and their presence will be guaranteed only if enough people in the West demand it. Which, comrade, means you.