No would-be U.S. president today would dare commit that wartime memory to their campaign biographies. Not the "right" tone for a commander-in-chief, anxious spin doctors would say.
But the blunt Truman, who became one of the White House's most impressive occupants, raises a telling question: How far should American presidents use military service to legitimize their claims to higher office?
The question is worth asking now that the current U.S. election campaign seems to have turned on the competing military backgrounds of John F. Kerry and George W. Bush.
Kerry won medals for his brief service as a patrol boat commander in Vietnam before going on to become a prominent anti-war veteran.
The combination of war hero and conscientious protester to a war most Americans now agree was mistaken, evidently threatens Bush who, having avoided Vietnam by serving in the Texas Air National Guard, is running on his record as wartime commander in chief.
Which is why some of Bush's wealthy supporters are spending lavishly on an advertising campaign to raise doubts about Kerry's war record. The campaign worries Democrats.
"When you're basically running on your biography, and there are ongoing attacks on the credibility of your biography, you have a really big problem," a leading Democrat confided to the New York Times.
Yes you do, but it's a problem that reveals as much about the shortcomings of American politics as about the current rivalry.
The U.S. is noteworthy in modern Western democracies for the high premium placed on military service as a prerequisite for political power.
Most European and Asian nations (with the exception of course of those under military rule) rarely focus on their leaders' military records -- if they have one.
By contrast, the world's most powerful civilian-led government seems to turn absolutely martial every four years. Of America's 43 presidents, 30 served in the military, and many self-consciously rode their war records to high office.
Yet some of the country's greatest leaders didn't need the aura of the front line.
Franklin D. Roosevelt was a Navy bureaucrat in Washington. Abraham Lincoln was briefly an Army captain, but in a blemish that would probably ruin his electoral chances today, he was thrown out of the service on disciplinary grounds.
John Adams, who followed Revolutionary War hero George Washington as the second president, never wore a uniform.
Did their military service (or lack of it) make a difference to their achievements?
The answer seems a resounding no.
It may have made sense in earlier periods of American history, when the country was groping its way in a world where war often defined the course of international affairs. Experience as a soldier supposedly demonstrated certain qualities -- patriotism, leadership, a "warrior" spirit -- that are otherwise impossible to measure.
But dwelling on military service (or the lack of it) seems retro now.
Today, a powerful CEO, a brilliant scientist, a diplomat, or even (well, this may be stretching it) an incisive journalist is as likely to have the moral and management qualities necessary to pilot the globe's only superpower through a complex geopolitical landscape.
Even President Dwight Eisenhower, who commanded allied armies during WWII, understood that wartime experience could be a distorting influence. "The kill-or-be-killed nature of combat tends to dull fine perceptions of right or wrong," he once acknowledged.
Here's the irony: The modern association of war and politics looms higher than ever in a period when relatively few Americans between 20 and 50 have ever seen the inside of a barracks.
Partly to blame is an American popular culture that glorifies combat, from movies to video games. But what should be worrying to anyone who relies on wise and prudent American leadership is the cynicism of U.S. politicians who exploit military rhetoric as a vote-catching tactic.
Today's spin doctors might learn from Capt. Harry Truman.
His WWI combat service paved the way for his entry into politics. But what got him noticed on the national stage was his WWII tenure as a U.S. senator.
He was investigating war profiteering and corruption on the home front.
Stephen Handelman, a frequent commentator on crime and terrorism for publications including the New York Times and the Toronto Star, is the author of Comrade Criminal: Russia's New Mafiya.