Associated Press File Photo / People run from the collapse of one of the twin towers at the World Trade Center in New York on Sept. 11, 2001.

America has become so used to social distancing that we wonder if that's how the terrorist attacks that occurred on Sept. 11, 2001, are being viewed today — with a social distance.

As in, they are something for the history books, something bad that happened a long time ago.

Nineteen years is a long time. After all, Americans born after 9/11 will cast their first presidential vote this fall. A lot has happened in this country between then and now.

Consider just a few things:

* The country became involved in two wars, one in Iraq and one in Afghanistan, in partial retaliation for the terrorist attacks. Indeed, we're still involved, though President Donald Trump said earlier this week he planned to cut troop presence to 3,000 in Iraq by the end of September and 4,500 in Afghanistan by late October.

* A subprime mortgage crisis fueled what became known as the Great Recession, the longest period of economic decline in the United States since the Great Depression of the 1930s.

* Americans elected and re-elected their first Black president, Barack Obama.

* Trump was elected president in one of the greatest upsets in U.S. political history, was impeached by the House while in office and was acquitted by the Senate.

* A Chinese-born virus swept across the world, enveloping the United States and killing 192,000 in the country.

With all that, it may be no wonder those first-time presidential voters aren't thinking about international terrorism when they go to the polls. Through three presidents, no subsequent international attack has occurred here.

We're glad that doesn't have to be a worry for them, but we hope they'll nonetheless understand that America cannot let its guard down in protecting its borders, in being a beacon for freedom around the world, and for waging peace and stability where possible.

The immediate period following the 9/11 attacks, in the months when this year's first-time voters were born but wouldn't remember, also marked the last time the country saw an extended period of unity. We don't delude ourselves that every American was united or that the period lasted for years, but believe such unity of spirit — not division, not separateness, the likes of which the country has seen this summer — still should be the goal of the first-time voters as they become adults.

For those who don't remember, citizens were as one in outrage that someone or some group had targeted us and come to our shores and killed 2,977 innocent people. Even today, for many whose family members were forced to die as their jet was cruelly directed into the World Trade Center or the Pentagon or brought down in a Pennsylvania field, the anger is palpable.

Only months after being elected when the U.S. Supreme Court put an end to an umpteenth recount of Florida votes, President George W. Bush was suddenly everybody's leader. We believed him when he said, speaking from a bullhorn in a mound of Twin Towers detritus, that those "who knocked these buildings down will hear from all of us soon." And even fans at New York City's Yankee Stadium cheered him when he threw out the first pitch at Game 3 of the World Series.

American flags were in big demand, and patriotism — 70% in a Gallup poll said they were "extremely" proud to be an American — was not a dirty word. At the end of the month that saw the terrorist attacks, the president had a 90% approval rating.

Of course, it didn't last.

The incursion into Iraq peeled off some of Bush's support, the inability to find weapons of mass destruction there disillusioned others and the typical partisanship of Washington, D.C., eventually resurfaced.

By Obama's election, the country had wars, a recession and an even more potent weapon — social media. Suddenly, even the least informed of us could hide behind a blizzard of words on Facebook, a limited but biting number of words on Twitter and disappearing words on other platforms. No permanency of newspaper, no prominency of television, but, snarky, hurtful and hateful nevertheless.

Partisanship hasn't had a chance since.

We wonder sometimes if Americans are social distancing from 9/11 because they don't want to remember how unified we were, if they prefer instead to hate each other instead of a common enemy, if they prefer to see us as the 9/11 terrorists saw us, if they prefer division and rancor instead of peace and harmony.

However, no one who truly understands why the country was founded, how it was built and how it still offers the world's best opportunities would feel that way. But sometimes, such as moments this summer when the country has felt so at sea, it feels like the terrorists won.