I have been thinking about my whereabouts and preoccupations on the day the called-off rescue mission was staged. At around 10:30 that morning I had just settled in as a spectator at a conference called "Totalitarianism and Terrorism, Foreign Policy Challenges of the Eighties." Criticism, much of it plausible to me, was being leveled against the Carter administration by a variety of conservative intellectuals -- including some high up in the Reagan campaign -- for its failures of audacity and clear-headness in facing the challenges under discussion. Carter had no long-term strategy for protecting American interests, it was generally agreed. He should be replaced by someone who had.

All this was being chewed over, according to accounts I have now read, at approximately the same time the eight American helicopters were entering Iranian airspace. By the time the first signs of real trouble were occurring, a colleague and I were having lunch in a restaurant near The Post, planning the next day's editorial. It would be an exhortation to Jimmy Carter not to back off the tough, pressuring policy he had enunciated toward Iran. At the end of the afternoon, as the now-written editorial was being edited and put into type, Carter was getting the word: the mission had failed, people were dead, the whole thing was a bust. He called it off, and we went to press.

The weird two-track existence -- my Thursday, and his -- highlights for me a more general gap between criticism, analysis and political perceptions on the one hand, and, on the other, the arena, the pit -- the day-by-day, hour-by-hour, messy chance-and accident-ridden place where imperfect people try to make good things happen . . . and don't. I'm not saying "Oh, poor him," or "The job is bigger than all of us" or anything like that. Those conferees' complaints about an absence of coherent strategey seem as sound to me today as they did that Thursday, and so does the editorial impulse to urge the president to hang tough. What interests me is that although the analysis seems right and true, it also always seems not quite practical or relevant or applicable to the particular can of worms into which the administration is staring at any given moment.

Partly, this is because theory is accident-free, without the complicating features of hydraulic systems or individual human foibles. Candidates and critics have the luxury of saying what they would do without actually having to do it. But it's not just that. It is the indestructibility of so many of these theories, the almost worshipful respect in which they are held, that seems to me the more important fact. They prevail over evidence, no matter what the evidence may be.

At the moment, the country, according to the televised and printed responses to the news of the failed mission, is in the familiar phase one of its reaction. We are in our "I-am-shocked-and-dismayed" mode, rumbling forth with calls for national unity, forswearing now and forever (want to bet?) politics and "scapegoats." But I don't figure this will last out one Newsweek cycle.It will be over by the middle of the week. We are, the whole lot of us in this country, trained like commandos ourselves, and at the signal you can be sure we will all take up our battle stations. The disaster in the desert will be seen as irrefutable further evidence of at least the following few theories -- and probably dozens more:

That a terrible rundown of our military equipment has been permitted, culminating in the scandalous and mortal failure of the helicopters en route to the Iranian rendezvous, and that the lesson is that the military procurement budget is woefully deficient.

That military action, even of this properly targeted kind, is a reckless, maniacal and doomed line of activity unfit to accomplish any of the objectives we have in mind.

That the military will always snooker the civilian leadership, given half a chance and that once more, as in the Bay of Pigs and Vietnam, it has led our government into the Big Muddy -- with no way out.

That Carter is a warmonger and a bloody-minded fool and that he acted at this time for political gain.

That Carter is unprecedentedly incompetent and weak, that he did too late and then in panic and unnecessarily called the whole enterprise off.

The episode, in other words, will most assuredly be used to discredit whatever we were already of a mind to discredit, and I don't think there can be any doubt that Carter will be at the top of the list. People are going around now lugubriously supporting him, but -- unless the thing has a surprisingly good outcome -- that can't last, and I wouldn't be surprised if this whole affair didn't finally do him in. It is ideally suited to that purpose, no matter which side (too weak and timid versus too military-minded) you are on. But while some part of all of the criticism seems valid to me. I also think there is a very large element of self-delusion in it.

When the ghastly history of the whole Iranian conflict is revealed, there will also be revealed some disturbing truths about how reasonable and even fairly fashionable ideas of what should be done were tried, how avenues got blocked off, how bizarre and almost comic episode intervened. Carter came equipped with a secretary of state who was anything but impetuous and a secretary of defense who is skeptical of and acknowledgeable about military bluff and overpromise as anyone alive.

What I am saying is that he is, for better and for worse, in many respects the rational, unexcitable, let's-look-at-it-case-by-case, unimperial, middle-road, humane president so many of us had penciled in for the post-cataclysm years. Yes, he has presided over some terrible foreign-policy setbacks and, yes, at least some part of this is due to his own nature. But I think we are all concentrating on this so we won't have to face the fact that so many of our own theories and prejudices have been discredited too. They are, as well, the lofty sentiments of the other fellows running for president now. Precisely to the extent that we make Carter the scrapegoat, we guarantee that we will have learned nothing from the infuriating and confounding episode that began in Tehran last fall.