After a trip to France last summer when President Emmanuel Macron invited him to observe the Bastille Day Parade, President Donald Trump started musing about doing the same thing in the United States.

But President Trump says a lot of stuff, and it’s hard to know which bad ideas to take seriously. This one, apparently, he actually intends to follow through on.

It would, of course, be a tremendous waste of money to ship tanks and armored personnel carriers and — who knows? — ballistic missile launchers to Washington, but that’s not our chief concern. It’s that such a display sends the wrong message to Americans and to the world about what the United States stands for.

Mr. Trump has said he wants such a parade to display the dominance of American military muscle. That’s generally been the motivation of dictators like North Korea’s Kim dynasty, and more often than not, the shows have been an exercise in Potemkin fakery and over-compensation. Those who really do have unparalleled military might don’t have to put it on display.

It is not totally unprecedented for the military to march through Washington, D.C.; such an event took place during George H.W. Bush’s presidency after the first Gulf War. And an American military parade has become mixed with presidential politics from time to time. Troops have marched in a handful of inaugural parades in modern times — mainly during the early days of the Cold War, including in Dwight Eisenhower’s first inaugural parade in 1953.

But Eisenhower, the supreme allied commander in World War II, was the president who warned America in his farewell address of the necessity for maintaining a strong military but also the dangers of allowing it to dominate the nation’s government, economic and spiritual life.

The idea that ours is a nation in which the military is subordinate is as old as the Republic itself. That principle was symbolically sealed in Annapolis in 1783 when George Washington resigned his commission as head of the Continental Army to return to private life. Not only did he do so voluntarily, but he did so in a way that reinforced where America’s true power lies — in the strength of its democratic institutions, not in its army.

The greatest former generals to serve as commander in chief understood that. But our current president, a draft dodger who claims it was treasonous for Democrats not to clap at whatever he said during a State of the Union address, clearly does not. We celebrate those who have served in the armed forces, no question. But it is not their strength we venerate but their willingness to sacrifice to safeguard those principles we hold so dear.

Our national holiday is the 4th of July, independence day. It is not the day our war to free ourselves from England began nor the day of our victory. On the contrary, it is the day when we declared our belief in our inalienable rights to freedom and self determination.

That is what makes America a beacon to the world. Sending tanks down the streets of the capital to flaunt or might does not.