You don't have to be a student of military conflict to know that America's high opinion of our troops, which soared during the World Wars and the Korean conflict, plunged during the Vietnam era.
Returning soldiers were held accountable for the president's decisions. Some have never recovered from feeling the contempt of their countrymen for being in the wrong war, under the wrong leader.
Things couldn't be more different today. Regardless of where individuals stand in their opinion of the conflicts in the Middle East, there's a national sense that the men and women fighting there are not to be blamed for it, but honored for having signed up.
To get a sense of how everyday Americans stand behind our men and women in uniform, scroll through a website like troopssupport.com. It's a directory of organizations that provide everything from free lawn care and baby showers for veterans and their families to job training and new homes for soldiers wounded in action.
This is wonderful, obviously. But it raises the question: Why have we embraced our soldiers so tightly this time around? Other than an appreciation for their sacrifice, is something else going on?
The questions began to consume me a few years back, after I wrote a column about The Liberty Limited, a temporary, multicar train that was assembled by Bennett Levin, a former Philly L&I commissioner and self-made millionaire.
The Liberty Limited carried wounded soldiers from Washington and from Bethesda, Md., to Philly for the Army-Navy game. I volunteered and saw firsthand the joy of troops reveling in their break from hospitals and rehab.
The column elicited huge response — more than a thousand emails, plus letters and phone calls — from readers eager to declare their love for our soldiers. Many were actively showing it, too, with single efforts like Levin's.
The do-gooders ranged from big-hearted teens, to single moms, to Harvard-trained shrinks and celebrities. Many spent substantial time, money and prayers on men and women they'd never met.
So I asked more than a hundred of these folks, "What is it about the troops that moves you so deeply?"
The thread connecting their responses revealed itself over time, in bits and pieces, beneath the surface of every phone conversation and email exchange:
"Because holding the troops in high regard is about the only thing that unites Americans today. And I am dying to feel united with my fellow Americans about something we agree upon unequivocally."
These are tough times in our republic, painfully fractured by politics, economics and culture.
We can't agree upon what it means to be an American. Or a patriot. Or a defender of family values. Or a protector of civil and constitutional rights. For so many of the troop-supporters I interviewed, the notion that America is as divided as countries they believed to be less special than the United States was both scary and disorienting.
Where they regained their balance was in the belief that we are united in conviction that the troops deserve our support. And, oh, how good it felt to agree, as a nation, about something so big and important.
"See," they thought, without even knowing they were thinking it, "THIS is what it is to be American: It is to be one who is willing to serve — and one who is willing to serve those who serve."
They viewed this generosity as an American trait but had become cynical and wary about giving not just their money but their very caring to causes that may not be worthy of the love. And it was, indeed, love that they were eager to give.
But not if it made fools of them.
That's a sentiment shared by most Americans. It's why we tend to embrace, say, charities that help children, who didn't ask to be born into whatever dire circumstances they find themselves. And it's why we aren't so fired up over causes that help, say, unwed mothers, prison inmates or others whom we feel very much had a say in creating their sad fortunes.
Our troops fall into a unique category: They are often in tough situations they did not create; they persevere heroically; and they do it for the sake of country.
It's a feel-good trifecta.
As a result, our soldiers are unequivocally qualified recipients of all the love, goodwill, compassion and loyalty that we have always identified as our most virtuous and generous qualities.
I think that our need to give wholeheartedly to others has for years been so stopped up, argued over or misdirected that it was bound to explode the way it has with support of the troops.
Their ever-presence in our headlines and their constant, worthy need, leads Americans back to what we believe is our best, collective self.