On Jan. 30, with a snowstorm bearing down on Washington, Carla Hayden, the librarian of Congress, tweeted a picture of a snowball fight at the U.S. Capitol. The 1923 photograph was a bittersweet glimpse into the archives, a reminder of a time when one of the city’s iconic buildings wasn’t bristling with police but was a place to make laws and even go sledding.

Less than a month after Donald Trump encouraged his supporters to storm the Capitol, it looks likely that the building could end up behind permanent security fencing, perhaps accessible only to people who work there or who have specific business with members of Congress. Temporary fencing, topped with barbed wire, encloses not just the Capitol, but also a “Green Zone” that stretches deep into the monumental core of the city. Last week, Yogananda Pittman, the acting chief of the U.S. Capitol Police, said permanent fencing may be necessary.

“In light of recent events, I can unequivocally say that vast improvements to the physical security infrastructure must be made to include permanent fencing, and the availability of ready, backup forces in proximity to the Capitol,” Pittman said in a statement.

It would be a tragedy if that happens. But these things generally play out according to a fixed script, and this little drama is already well underway. First, there is a massive failure of security. Then, security experts call for closing streets, erecting barriers and fences, and limiting public access to public buildings. Local leaders protest, but those protests are futile, and rigid new security protocols are enforced. The fences never come down; the streets are never reopened. Thus it happened after the Oklahoma City bombing of 1995, which led to the closure of Pennsylvania Avenue in front of the White House, and after the Sept. 11, 2001, terrorist attacks, which radically transformed important public buildings, not just in Washington, but across the country.

But this time should be different, because the situation is different, and the building — the preeminent symbol of our democracy — is too important to lose. What happened on Jan. 6 had nothing to do with fences or barriers or bad security infrastructure at the Capitol. It was a human failure, not an infrastructure failure. Investigations are ongoing, but it’s already clear this was a tragedy of incompetent leadership, failed intelligence and a giant mess of missed or crossed communications. And yet some of the people involved in the debacle may be instrumental in deciding on security measures.

The short-lived insurrection was planned and executed in public. There was no doubt it was coming. There was no uncertainty about the toxic ambitions of the men and women who led the mob. They made it all clear on social media. And there was never any doubt that Trump was capable of and willing to incite the crowd. The fail-safe way to predict what Trump would do was to imagine the worst that he might do and assume he’d do just that.

And yet, because our leaders lacked imagination and foresight — because our lawmakers and the security personnel who protect them were unwilling to acknowledge the toxicity, including rampant racism, in plain sight — they would now disfigure a building that they occupy only at the sufferance of the electorate.

Even worse, they would fortify and severely disrupt one of this country’s finest cities against a menace that can be stopped only where it is brewing, outside of Washington, a city whose residents almost universally reject and abhor the ideology of the Proud Boys, Oath Keepers, QAnon cranks and neo-Confederates who invaded the Capitol.

To understand the gravity of what could happen if security bureaucrats were allowed to seal the Capitol within a fortified perimeter, it’s necessary to grapple with an apparent contradiction: The U.S. Capitol isn’t particularly great architecture, which is why it would be an architectural loss to fence it in.

The importance and meaning of this building lie mainly in its use, its function, its activity. The building itself is a bit of a hodgepodge, the product of more than two centuries of additions and renovations, incorporating the ideas and vision of multiple architects. Like a rambling farmhouse, it has grown enormously over the years as the American family has grown, from two smallish legislative chambers connected by a wooden walkway to a sprawling and rather awkwardly distended building with more than 600 rooms, 1.5 million square feet and, since 2008, an enormous basement and visitors center.

The magic of the building has more to do with its homely approachability than its size or magnificence. Because it sits atop Jenkins Hill (as the almost 90-foot rise of Capitol Hill was once known), it is visible throughout much of Washington. Like a cathedral on the skyline of a European city, the Capitol governs by omnipresence, yet even for longtime D.C. residents, there’s always a little thrill when you get near it. That experience is fundamental to democracy: You think, as you approach the building, that you shouldn’t be allowed to get so close to something so important, so essential, so historic, and then you realize that you live in democracy and that this kind of access is exactly what democracies do.

That delightful juxtaposition of thoughts — reverence mixed with a sense of both danger and responsibility — is how democratic states survive. They take risks to remain open, and that openness is rewarded with a sense of service and even loyalty among the governed. Few, if any other, government buildings in Washington enact that drama so clearly.

The White House is a mansion, and a home, and access will always be limited by the extraordinary security demands of protecting the president and his or her family. The U.S. Supreme Court is the city’s ivory tower, and it revels in a sense of cloistered detachment from the hurly-burly of civic life. The Capitol, however, is the people’s house, and while closing it might afford some minimal improvement to the security of Congress, it would only exacerbate the populist anger seething in America.

And it is that anger that security efforts must address. Before one foot of fencing is made permanent, we need to know everything we can about who attacked the Capitol, who led them, where and how they communicated, where they are now, and what they are planning next. After the 9/11 attacks, the enemy seemed far away and unpredictable, so of course too many Americans were willing to accept severe infringement on their liberties. Today, the enemy is within, and it isn’t difficult to predict what it will do.

The next attack on the Capitol will involve people with guns and other weapons driving cars or taking trains and planes to Washington. They should be stopped before they can do that — stopped where they are now — not at barricades that wall off our elected representatives from the people they serve. Indeed, some of the heavy-handed security measures that were put in place in response to 9/11, including no-fly lists, might at least be repurposed to defend against right-wing militias and homegrown fascists.

In the weeks since the failed insurrection, it’s been hard to measure the severity of the damage done to our country. People died, including a member of the Capitol Police, who was injured during the riot. So, it’s a gravely serious matter. But many of the people involved seem to be louts and simpletons, in thrall to conspiracy theories so outlandish that ordinary people can’t even imagine what it might be like to believe such codswallop.

Along with the grief of those who lost loved ones in the attack, the lasting, real damage of Jan. 6 will be symbolic. Closing off the Capitol would be an enormous symbolic victory for the rioters engaged in acts of insurrection. It would prove their power to permanently alter civic life, further divide our elected representatives from the people who elect them, exacerbate the perceived illegitimacy of democratic governance, and inflame ideas about elite leaders no longer answerable to the people.

It would give permanent architectural expression to the sad and self-defeating ideology of the insurrectionists themselves: fearful and angry and closed off from genuine civic life.