Jeane Kirkpatrick (splendid statesman, novice politician) should heed the words of Douglas MacArthur (great general, lousy presidential candidate), who said most military disasters can be explained in two words: ''too late.'' Too late in perceiving, too late in preparing for challenges.

As this is being written, Kirkpatrick is in the final stages of considering a tardy entry into the Republican nomination scramble. That scramble has been under way for several years and may be settled in fewer than 140 days, on March 8, ''Super Tuesday.'' By running now, Kirkpatrick probably would diminish herself and might contribute to an outcome she does not desire, the nomination of George Bush.

Diminution would be the result of a candidacy that would allow her to be a brief sparkler before subsiding to the role of just another candidate with single-digit support. A jerry-built campaign would suggest a streak of unseriousness. If she runs she will learn, abruptly, something learned last summer by a man with years of Republican politicking to draw upon.

The candidacy of Paul Laxalt sank last summer when he discovered that by waiting until last spring to get busy he had started too late -- too late to recruit key activists, too late to shake the money tree. Some Laxalt supporters have urged Kirkpatrick to run. They, especially, should know better.

For several years Kirkpatrick, when encouraged to run, demurred, citing, among other things, her friendship with Jack Kemp. Kirkpatrick knew what is still true: many of her votes would come at Kemp's expense. She said she could not consider running unless it became clear that Kemp's candidacy was failing. The insoluble problem was that by the time it might become clear that Kemp was failing, it would be too late for her to succeed.

It is not yet clear that Kemp's strategy cannot work: it depends on doing well in New Hampshire while either Bush or Dole falter. The only conceivable Kirkpatrick strategy would be to skip Iowa, do well in New Hampshire, then improvise frantically. But in New Hampshire she would cannibalize Kemp's support. And even if she did well, she would have just three weeks to raise the necessary money -- $4 million, minimum -- and do the innumerable other things necessary for competitiveness on Super Tuesday.

Bush is off to a staggering start, and Dole is on a roll. Dole is now raising money as fast as Bush, and has acquired two new allies who are important substantively and symbolically. His new campaign chairman is Bill Brock, who as GOP chairman from 1977 through the 1980 election did more than anyone besides Reagan to make possible the election of Reagan. Richard Wirthlin, who has been Reagan's pollster for more than 20 years and had joined Laxalt, is joining Dole.

Furthermore, to the extent that the unpleasantness on Wall Street tarnishes Reaganomics, it tarnishes Bush's association with Reaganomics. To the same extent it enhances Dole's stature as the candidate who has most consistently treated the deficit as a problem that (in Dole's recent words) will not go away or grow away.

Bush wants developments concerning other candidates to delay as long as possible the day when he is one-on-one with any opponent, particularly Dole. By prolonging the confusion on the conservative side, a Kirkpatrick candidacy would assist the candidacy of Bush, the man least likely to take her as a running mate or include her in an important position in his administration. She and he are not two souls with but a single thought, two hearts that beat as one.

In fact, if Kirkpatrick has a serious politician's interest in using power to shape events, she can do so spectacularly, anytime between now and when the voting starts in Iowa. (After that, any endorsement of anyone by anyone will be of marginal importance.) Were she to endorse Dole now, she would confer upon him an imprimatur invaluable in the continuing competition for the hearts and minds of conservatives. And she would assist the man whose admiration for her was made manifest when, in suggesting improvements for the Arias Central American peace plan, he drew heavily on her advice.

One suggested reason for running refutes itself. She would be the first woman candidate who would not be a thought of as a ''woman candidate,'' the first whose ideas would be everything, her chromosomes irrelevant. But to run for that reason would transform her into someone trading on an irrelevancy.