Walking down the Boulevard of the Allies to work last Friday morning, I noticed a cop standing by a street barrier.

"What's this about?" I asked, assuming it had something to do with the Tom Cruise movie currently shooting around the Golden Triangle.

The officer looked at me as if I'd just beamed in from the Andromeda galaxy. "It's Veterans Day," she said. "There's a parade this morning."

Of course I was embarrassed. Veterans Day gets a bit less hype than some of the other holidays we Americans celebrate. If you're not careful, it can slip by like an unruly gust of wind.

When I made my way through the modest crowd a few hours later, the most natural thing to do was to applaud the men and women in uniform who paraded down the Boulevard of the Allies at lunchtime on an overcast day.

The faces of these veterans, some of whom fought in wars before many of us were born and others who were in combat as recently as the fighting in Afghanistan, were interesting. Their expressions ran the gamut from pride to dignified wariness to the blank stares every war imposes on its most thoughtful combatants.

School marching bands provided the soundtrack, a swirl of patriotism and pomp. There was no confetti, but plenty of miniature flags along the sidewalk greeted the soldiers. Cell phone cameras turned nearly everyone in the crowd into civilian paparazzi eager to chronicle the event.

Men who never thought of themselves as particularly heroic while being fired upon at Khe Sanh or Fallujah marched in formation. Those who survived winter fighting on the Korean peninsula two generations ago rode stoically on parade floats. Batons twirled and color guards marched in synchronized battalions around them. It was pure Americana.

Shortly before noon, a group of men and women crossed the intersection of Stanwix and the Boulevard of the Allies. Some wore vaguely military-looking jackets, but most wore street clothes that had seen better days.

This group was a rainbow coalition of Pittsburgh humanity. Dreadlocks, bald heads and mussed, gray hair were well represented among the marchers. Some carried signs that wouldn't have been out of place at Occupy Pittsburgh. I recognized many of their faces.

They were people we've all seen or pretended not to see on street corners or huddling together under bridges around town. Without knowing anything about their circumstances, we assume they're dependent on the kindness of strangers whether they're panhandling or not. We rarely consider the possibility that we're indebted to them for anything.

The battalion of homeless veterans kept ragged formation four or five people across and at least that many rows deep. They were not stoic as they marched into the parade's home stretch.

They smiled and returned the waves of their fellow Americans who cheered them from the sidewalks. The Veterans Day parade is the one day of the year that these dispossessed men and women are seen by the public as fully vested members of society.

As former warriors, they are not objects of pity. Their service to the country is acknowledged by all, even if it won't amount to anything tangible like a warm bed or a full stomach. At that moment, there is nothing more tangible or more important to them than respect.

The battalion of homeless veterans may be satisfied with our expressions of gratitude, but they are, in the end, a rebuke to our moral complacency. We honor them with our lips and our frantic flag waving, but dishonor them by allowing them to slip between the cracks of our increasingly porous social welfare net.

Though the population of homeless veterans nationwide has declined in recent years from a reported high of about 400,000 in 2004 to an estimated 135,000 today, the percentage of Iraq and Afghanistan veterans among the homeless is growing. With thousands of service members scheduled to leave Iraq by Christmas, the ranks of homeless vets will most likely grow unless the economy miraculously turns around.

Last year, an estimated 13,000 veterans under 30 were homeless, according to a joint report by the Department of Veterans Affairs and the Department of Housing and Urban Development.

The indifference to their sacrifice is intolerable in a country where less than 1 percent of us currently serves in the military. The next homeless person we meet should make us wonder whether we're already at a moral disadvantage.