A false alarm over supposed gunshots turned Kennedy Airport from a scene of boredom into bedlam last month. Travelers huddled behind chairs and luggage, ran for exits, even sought safety on the tarmac, to escape a perceived attack.

The danger seemed real.

Thankfully, it wasn’t. But the quick toggle between regular life and extreme danger shows the way we live now, 15 years after 9/11, when an attack was real.

The days after that event brought out the best in many New Yorkers, determined to keep going as normal in what seemed to be a changed world — changed because of the first responders and victims who didn’t return home. Changed because of the threat that the carnage might be repeated. We had entered a more precarious world than the one in which we started the week. A similar attack didn’t happen and other attempts were thwarted, but the world changed around us. In some ways we changed it — with long wars in Afghanistan and Iraq launched in the name of our safety and revenge.

Did they make us safer? Perhaps the one thing that our Republican and Democratic presidential candidates can agree on is that our interventions stirred a pot that gave birth to the Islamic State. The terrorist group provokes continued wariness of attacks at places like Kennedy Airport; New Yorkers with vivid memories follow the flight paths of airliners on approach to land.

Is this post-9/11 fear warranted? To quell it, we’ve surrendered our shoes and metadata, built towering counterterrorism surveillance infrastructure, put our troops in harm’s way and killed civilians halfway around the world. What has it gotten us? No new answers about how to bring peace and safety to troubled areas of the world.

This low-grade but still consequential fear, warranted or not, does not seem to be dissipating, even 15 years on. Even with extra layers of security, we have largely maintained the way we lived.

In New York City, we have rebuilt some of what was lost. We still gather. We still try to be open and welcoming. We might worry, but we still fly.