This article has been updated to reflect news developments.

In the winter of 2001, as a trainee at the Army’s combat engineer school at Fort Leonard Wood, Mo., I learned how to stop a tank dead in its tracks. I learned how to use tubular 40-pound cratering charges wrapped in blocks of C-4 to blow a ditch as deep and wide as a school bus. I learned to lay mines capable of blowing the tracks off a tank.

But even as I was learning those skills, they were already outdated. The collapse of the Soviet Union a decade earlier made it improbable that American troops would ever have to defend Western Europe against tanks. In 21st-century wars, we soldiers would almost never confront an enemy tank, though all of us would come to fear the enemy’s capacity to make a mockery of American armor using kitchen explosives.

With a few exceptions — the invasion of Iraq in 2003, the battle of Falluja in 2004 — the tank has become as irrelevant to modern warfare as the horse cavalry it replaced. Primarily designed to roll over fences and trenches and to knock out other tanks in World War I-type and World War II-type battles, tanks have been reduced to serving, in effect, as heavy, expensive bunkers. They struggle to maneuver anywhere but open terrain (which means they are as likely to become an obstacle as they are to breach one) and they bleed the supply chain (it takes about 10 gallons of fuel just to start an M1 Abrams tank, and its engines get fewer than two miles per gallon).

So what are we supposed to make of President Trump’s fascination with these hulking relics and his decision to display them in Washington during Thursday’s Fourth of July celebration, flanking himself with M1A2 Abrams tanks and Bradley armored vehicles as he delivered a tribute to America’s armed forces?