GOP presidential nominee Donald Trump campaigns in Scranton

Republican presidential nominee Donald Trump, and his vice presidential nominee, Mike Pence, campaign at Lackawanna College in Scranton, Pa., Wednesday, July 27, 2016. Dan Gleiter, PennLive.com

PHILADELPHIA - By any measure, retired Marine Gen. John R. Allen is an American hero.

But Donald Trump thinks he's a failed general.

"They had a general named John Allen, and he -- I never met him," Trump said during a Friday campaign rally of Allen, who delivered a forceful endorsement of Hillary Clinton during this week's Democratic National Convention here.

"And he got up and he started talking about Trump, Trump, Trump. Never met him. And you know who he is? He's a failed general."

He added: "He was the general fighting ISIS. I would say he hasn't done so well, right? Not so well."

Let's take a moment to consider Trump's and Allen's respective biographies.

Allen, 60, an honors graduate of the United States Naval Academy, commanded American forces in the Balkans in the 1990s. He served in Iraq from 2006 to 2008, overseeing U.S. troops in Al Anbar province, according to a Department of Defense biography that paints a picture of a thoughtful warrior.

Allen was the Obama administration's top choice to oversee U.S. and NATO forces in Europe. Instead, Allen retired to take care of his wife, who has chronic health issues, The Washington Post reported.

He came out of retirement in 2014 to command the International Security Assistance Force in Afghanistan, The Post reported.

And he's a failure?

Then there's Trump.

The 69-year-old real estate magnate, who received medical and academic deferments from service in Vietnam, went to a military high school in upstate New York.

There, depending upon you believe, he either did so well that he was promoted to a prestigious post or was reassigned because of a hazing incident, according to published reports.

True, battlefield experience is no longer a prerequisite for the presidency. Neither Democratic nominee Hillary Clinton, nor her husband, former President Bill Clinton, served in the Armed Forces. The same is true of current President Barack Obama.

The last presidential aspirant with a serious military resume was U.S. Sen. John McCain, R-Ariz.

The former Naval aviator spent five years as a prisoner of war in North Vietnam He endured hideous torture and refused release out of respect to his fellow prisoners.

And we all know what Trump thinks about him.

"He's not a war hero. He's a war hero because he was captured. I like people who weren't captured," Trump said in Iowa in 2015. His remarks were sharply criticized by the Republican establishment at the time. Trump later backtracked.

On the campaign trail this year, Trump has been publicly critical of the nation's defense and intelligence establishment for not doing enough to contain the Islamic State, which presents a complex and multilateral threat to global security.

And there's a discussion to be had there over whether the Obama administration properly recognized the threat that the militant group posed.

But the idea that Allen is a "failure" for not singlehandedly defeating a shadowy terrorist organization engaged in assymetrical warfare, simply because he had the temerity to publicly criticize The Great Man, is both ridiculous and offensive.

But it's hardly a surprise.

At Trumpapalooza in Cleveland last week, the new GOP nominee told the baying crowd that "I alone" had the tools to fix the economy, repair relations between law enforcement and to fight terrorism abroad.

And anyone who stands in the way of that single-minded vision of Donald J. Trump as the cure-all to the nation's ills is a "failure." Or he's "little" or she's "crooked," or they're some other schoolyard taunt.

Those are the words of a Third World strongman, not those of a future president of the world's most powerful constitutional republic. No one leader solves America's problems on his own.

He - or now, perhaps, she - does it with the assistance of the military and civilian power structure.

Trump has tried to claim the mantle as the defender of veterans and the military this election season.

He's done that even as he's charged that the military is "a disaster." And he only made a $1 million donation to veterans' groups after the Washington Post exposed that he hadn't honored such a pledge.

In Philadelphia this week, Clinton and her surrogates painted a different picture of the American military.

It would be familiar to anyone who's ever met a soldier or an airman or a sailor.

It's a strong and brave force, comprised of young men and women of all races, ethnicities and religions who are backed up by support from a government that spends more on defense than the next seven nations combined.

There was perhaps no more moving or powerful a moment in Philadelphia this week than when Kzir Khan, a Muslim and a Pakistani immigrant, spoke forcefully against Trump.

The elder Khan's son, Army Capt. Humayun Khan, was killed in action in 2004 when a car loaded with explosives blew up at his compound.

Taking a copy of the U.S. Constitution from his suit pocket, the elder Khan offered to lend it to Trump.

"Look for the words 'liberty' and 'equal protection of law,'" he said, waving the paperback document as the crowd roared its approval.

Here's a reminder for Donald Trump: That's the document that you would be sworn to uphold if you're elected in November.

It was the document that John R. Allen swore to defend during a distinguished career in the Marine Corps and under whose protection he spoke his mind this week. It was the one that McCain valued enough to endure torture and privation.

It was the document that Humayun Khan, whose coreligionists Trump says he wants to ban, died defending in service to his nation.

They're not losers. They're not failures. They're heroes.

But that's Trump. He'll always have your back - as long as you're winning and never question him.