Something has come into my hands that I think is worth sharing. Prof. Fred I. Greenstein of Princeton, author of "The Hidden Hand Presidency," a study of President Eisenhower, has called my attention to a letter Eisenhower wrote 27 years ago which he says has never been published in full.

With the permission of the president's son, retired Gen. John S. D. Eisenhower, I am giving it circulation through this column. I think it is as important a statement on nuclear war as I have ever read.

Richard L. Simon, president of the publishing firm of Simon & Schuster, had written Eisenhower on March 28, 1956, calling attention to a column by Joseph and Stewart Alsop on the Soviet military threat, and urging "that a crash program for long-range airpower and missiles" be given the highest priority, as they recommended.

This is the Eisenhower reply of April 4, 1956:

"Dear Dick:

"Thank you for your letter, which brings up subjects too vast to be discussed adequately in a letter. Suffice it to say here that I doubt that any columnist--and here I depend upon hearsay as I have no time to read them--is concerning himself with what is the true security problem of the day. That problem is not merely man against man or nation against nation. It is man against war.

"I have spent my life in the study of military strength as a deterrent to war, and in the character of military armaments necessary to win a war. The study of the first of these questions is still profitable, but we are rapidly getting to the point that no war can be won. War implies a contest; when you get to the point that contest is no longer involved and the outlook comes close to destruction of the enemy and suicide for ourselves--an outlook that neither side can ignore--then arguments as to the exact amount of available strength as compared to somebody else's are no longer the vital issues.

"When we get to the point, as we one day will, that both sides know that in any outbreak of general hostilities, regardless of the element of surprise, destruction will be both reciprocal and complete, possibly we will have sense enough to meet at the conference table with the understanding that the era of armaments has ended and the human race must conform its actions to this truth or die.

"The fullness of this potentiality has not yet been attained, and I do not, by any means, decry the need for strength. That strength must be spiritual, economic and military. All three are important and they are not mutually exclusive. They are all part of and the product of the American genius, the American will.

"But already we have come to the point where safety cannot be assumed by arms alone. But I repeat that their usefulness becomes concentrated more and more in their characteristics as deterrents than in instruments with which to obtain victory over opponents as in 1945. In this regard, today we are further separated from the end of World War II than the beginning of the century was separated from the beginning of the sixteenth century.

"Naturally, I am not taking the time here to discuss the usefulness of available military strength in putting out 'prairie fires'--spots where American interests are seriously jeopardized by unjustified outbreaks of minor wars. I have contented myself with a few observations on the implications of a major arms race.

"Finally, I do not believe that I shall ever have to defend myself against the charge that I am indifferent to the fate of my countrymen, and I assure you that there are experts, technicians, philosophers and advisers here, who give far more intelligent attention to these matters than do the Alsops.

"With warm regard, sincerely, Dwight D. Eisenhower."

The letter was marked "personal and confidential." But if ever there was a message that echoes across the decades to our own time, it is this one.

In eight short paragraphs, the remarkable man who led the Allied armies to victory over Hitler and served the nation as its last two-term president, distilled a lifetime of wisdom.

There is one sentence which deserves to be carved in stone, or better, imprinted on the mind of anyone who occupies the Oval Office. Just read it slowly--clause by clause--and think about it:

"When we get to the point, as we one day will, that both sides know that in any outbreak of general hostilities, regardless of the element of surprise, destruction will be both reciprocal and complete, possibly we will have sense enough to meet at the conference table with the understanding that the era of armaments has ended and the human race must conform its actions to this truth or die."