SHUT IT down and close it up. That seems to be the default reaction of the Secret Service to any problem or failing — including its own — in protecting Washington buildings. The bunker mentality has turned the nation’s capital into a place of unsightly bollards, barriers and guard booths. This week it struck again. The loss this time is not just of access to a sidewalk that offered a glorious view of the White House but further erosion of the openness that is — or should be — a hallmark of American democracy.

As of 11 p.m. Wednesday, by decree of the Secret Service, members of the public were barred from the sidewalks along the south fence of the White House between West Executive Avenue and East Executive Avenue. Since 2015 similar restrictions had been in place overnight (between 11 p.m. and 6 a.m.), but during the day Washingtonians and visitors could still enjoy a classic view. The vantage point was hardly close to the White House, but it was a favorite spot for thousands of visitors to take a picture and hope for a glimpse of someone famous or powerful on the distinctive portico.

A spokeswoman for the Secret Service framed the change as limited; there are no new barriers or fences, Cathy Milhoan told us, and visitors can still get that iconic view of the White House from the other side of the street. Of course, they are now pushed farther back and separated by three additional fences; good luck getting a picture without signs warning “Restricted Area. Do Not Enter.” And this is just the latest in a succession of closings that have turned parks into parking lots for White House staff, walled off walkways and pushed Americans steadily farther from the buildings that belong to them.

The Secret Service faces enormous challenges to protect the nation’s leaders and historic structures in difficult times. But for all the talk about a careful balancing between openness and security, who speaks for openness each time one of these internal debates takes place? Fear and convenience seem to win out. It also seems that new curtailments on the public follow instances in which the Secret Service is embarrassed by security lapses such as last month’s incident in which a man scaled the fence and roamed undetected for nearly 17 minutes while President Trump was inside the White House.

A new, taller — and presumably harder-to-scale — fence is in the works for the White House. We support that project. Logic might suggest that, once it is in place, some access might be restored for the public. But don’t count on that. Once put in place, security measures generally stay forever. Just ask the commuters who used to drive on E Street or the businesses that closed when side streets were shut down.