It’s hard to think of an occasion quite like the posthumous award of the Medal of Honor Tuesday to two GIs from World War I. Private Henry Johnson and Sergeant William Shemin had been slighted a century ago because one was African American and the other Jewish.

President Obama spoke beautifully when he honored Johnson and Shemin with our nation’s highest award for valor. It can’t be entirely a coincidence that they were both from New York, the most gloriously diverse city in America.

Their stories give us something to think about as our nation is retreating from a war it already seemed to have won. For about both Shemin and Johnson one thing can be said above all others — they just weren’t going to accept defeat on the field of battle.

Johnson appeared in arms at the Argonne. He’d joined the all-black 15th New York Infantry, a National Guard unit that became the 369th Infantry Regiment, or the “Harlem Hell Fighters.” In Europe, the unit was shunned by our own white soldiers.

Not, though, by General John J. “Black Jack” Pershing, who’d come to respect black GIs and gained his nickname by serving as an officer of the black unit known as the 10th Calvary, or Buffalo Soldiers. Pershing turned around and advanced the Hell Fighters to combat under the French.

Johnson and another private, Robert Needham, were pulling sentry when a raiding party of as many as 24 Germans sprang upon the pair. What happened next reminds me of Creighton Abrams’ wisecrack in World War II: “They’ve got us surrounded again — the poor bastards.”

First Johnson, already wounded and under heavy fire, fought them off with his rifle. When it jammed, he held the rifle by the barrel and clobbered them with the stock.

Then he pulled out his bolo, and commenced a knife fight. Eventually, Johnson slugged the German Empire with his fists.

Sergeant Shemin appeared with the 4th Infantry Division, known as “the Ivy” because the Roman numeral four is IV (its four-leaf green patch symbolizes tenacity). Shemin was entrenched, separated from the enemy by 150 yards that President Obama called a “bloodbath.”

“Soldier after soldier ventured out, and soldier after soldier was mowed down,” as Obama told the story Tuesday at the White House. “So those still in the trenches,” the president continued, “were left with a terrible choice: die trying to rescue your fellow soldier, or watch him die, knowing that part of you will die along with him.”

Shemin, the president related, “couldn’t stand to watch.” First he leapt from his trench to rescue a wounded comrade, then he did it again and again, saving three GIs. When his officers fell, he took command of his platoon.

Johnson was by no means the first black GI, nor was Shemin the first Jewish GI to have been decorated with the Medal of Honor. At least 16 Jews have been awarded the blue ribbon with white stars, according to the account of the Jewish Virtual Library Web site, including three before Shemin in World War I.

Some 87 African-American men have been awarded the highest medal. They include one sailor, Robert Augustus Sweeney, who was decorated with the Medal of Honor twice, for separate incidents in which he dove into treacherous waters to save a seaman who’d fallen overboard.

Nor were Johnson and Shemin denied the glint of glory. Johnson was legendary by the time he returned from France. He’d been awarded the Croix de Guerre by France, and he would march with the Hell Fighters in a victory parade up Fifth Avenue.

Johnson went on a lucrative lecture tour. It lasted until, at St. Louis, the Hell Fighter “veered,” as historian Colin Grant put it, “wildly from the script and exposed the special grievances black soldiers felt” over the refusal of white soldiers to share trenches with them.

Shemin, whom America decorated for valor in 1919, was less bitter. “Let’s move on,” he’s quoted by Syracuse.com as telling one of his daughters, Elsie, after one of the GIs he’d saved told her that her father had been passed over for the Medal of Honor because he was Jewish. She still fought for years for his recognition.

It’s not my purpose here to politicize this story, merely to reflect on the meaning of the lives of Johnson and Shemin. What an inspiration they are at a time when our nation may yet have to spring from its trench and go back into combat to secure its victory.

This column first appeared in the New York Post.