As time is measured, it happened so long ago, the cruel war that refuses to remain submerged in the dustbin of history. Flexing its military muscle, the United States overpowered Mexico in the 1846-48 war which was denounced by Ulysses S. Grant as "one of the most unjust (wars) ever waged by a stronger against a weaker nation."

Heroism emerged on both sides, but in Mexican history an exalted place of honor exists on behalf of the memory of Los Heroes Ninos. This is the appellation given to the six young cadets who fought desparetely to the end in the decisive battle at Chapultpec Castle in Mexico City. Los Ninos Heroes were all killed. They entered the realm of mythology. In Mexico City they are not forgotten.

This is who they were: Juana de la Barrera, 19; Agustin Melgar, 16; Vicente Suarez, 14; Fernando Montes de Oca, 16; Francisco Marquez, 13; and also Juan Escuita, 20, who wrapped himself in the Mexican flag and, to prevent it being captured, plunged to his death from the castle's highest wall.

I consulted Howard Karno, the [San Diego County] book dealer who specializes in Latin-American history. "Sometimes the facts and the myths bend together," Karno says. "Nobody knows exactly what happened at the Alamo. But there were Los Ninos and they were heroes."

INTEREST SPURRED BY BIOGRAPHY

My interest in Los Heroes Ninos was spurred by reading "Truman," David McCullough's Pulitzer Prize-winning biography, a fine piece of work. McCullough writes at one point of a comparatively unpublicized event: President Truman's visit to Mexico in 1947. The trip was Truman's idea and, McCullough writes, "the acclaim was thrilling."

Delighted, Truman returned the "Vivas!" of the throngs--one woman shouted: "Viva Missouri!" To the Mexican legislature, Truman said: "I have never had such a welcome in my life."

The next morning, Truman announced suddenly that he wanted to make an unscheduled stop at Chapultepec Castle where, McCullough writes, "he did more to improve Mexican-American relations than had any president in a century. Within hours, as the word spread, he became a hero."

McCullough writes further: "As Truman approached, a contingent of blue-uniformed Mexican cadets stood at attention. As he placed a floral wreath at the foot of the monument, several of the cadets wept silently. After bowing his head for a few minutes, Truman returned to the line of cars where the Mexican chauffeurs were already shaking hands with the American passengers."

The visit of the American president, a century later, created a sensation in the Mexican press. One headline read: Rendering homage to the Heroes of '47, Truman heals an Old Wound Forever." Another headline read: "Friendship Begins Today."

A cabdriver in Mexico City, near tears, told a visiting reporter: "To think that the most powerful man in the world would come and apologize." A prominent Mexican engineer was quoted: "One hundred years of misunderstanding and bitterness wiped out by one man in one minute. That is the best neighbor policy."

HAILED AS 'THE NEW CHAMPION'

Miguel Aleman, the president of Mexico, hailed President Truman as "the new champion of solidarity and understanding among the American republics." American reporters asked Truman why he had gone to the monument to Los Ninos Heroes at the site of the battle of Chapultepec Castle.

Harry Truman, who knew about combat as a captain of artillery in World War I, replied simply: "Brave men don't belong to one country. I respect bravery wherever I see it."

After the end of the three-day visit, the Truman party departed on the presidential plane, The Sacred Cow, before dawn had come to Mexico City.

McCullough writes: "Moonlight reflected on the plane's wings as Truman looked out the window. Despite the hour and the chill morning air, a thousand people had come to see him off."

Perhaps you were aware of this footnote to history. I'm afraid that I wasn't.