SEN. KENNEDY has an interesting sense of history -- both the long sweep and the only yesterday kind. You don't have to have been a friend of the deposed shah of Iran or an apologist for the depredations of his secret police to know that Mr. Kennedy's characterization of the shah's regime as "one of the most violent . . . in the history of mankind" doesn't leave any language available at all for the truly special monster regimes of ancient and modern history, those that in fact would qualify as the most violent. If the shah had been the total beast Mr. Kennedy now depicts, right up there in the -- let us say -- Adolf Hitler and Joseph Stalin class, what on earth was President John F. Kennedy doing receiving him in Washington? What was Sen. Edward Kennedy doing paying him a visit in 1975?

Yes, we know -- Sen. Kennedy has said he did criticize the shah while the shah was in office, and he did also take the occasion of his visit to Iran to question the wisdom of the Iranian arms buildup. But the man he described in his Sunday night attack on the shah was not someone you merely criticize , meanwhile paying a call on. Do you think while howdy-and-shaking, as in the accompanying photograph, Mr. Kennedy was saying: You, sir, run one of the most violent regimes in the history of mankind and (the rest of the allegation) are stealing umpteen billion dollars and care only for yourself? Doesn't look like it.

If there was a time to say that, surely it was then and not now. The shah's cruel successor has sought to camouflage his own depredations by demanding that the shah be called to account -- and Sen. Kennedy asserts as simple truth the ayatollah's claims. Yesterday, as the predictable and justifiable uproar was heard, Mr. Kennedy backed off some. Yet the damage in this tense situation was done. It wasn't right, it wasn't responsible, and it wasn't smart.