When I came out yesterday morning, there were helicopters over my neighborhood.

I couldn’t see them from the sidewalk. Buildings were blocking the view. But a few blocks south of me, two or three of them were definitely hovering up there. And it wasn’t the sound of puny news copters grabbing Ground Zero live shots. This was the low, heavy rumble of military-style police aircraft, the kind sent to the sky to deliver a message or to fight a war.

Call it "the soundtrack of Terror New York." Usama bin Laden is dead now. What are we supposed to do?

Feel a sense of satisfaction, of course. That’s only natural. Accept the circle of revenge. But in practical terms, no one can possibly know what is coming next – or when. And no one has devised a reliable method for protecting us from it. But in times of anxiety like this one, everyone wants to do something. So the NYPD Air Force takes to the sky.

“We certainly are not taking any chances,” Police Commissioner Ray Kelly said yesterday with the mayor at Ground Zero, which finally looks more of a construction site than a giant hole in the ground. “Our assumption is that bin Laden's disciples would like nothing better than to avenge his death by another attack in New York. That is our current operating premise.”

Who has a better premise to share?

As we close in on the 10th anniversary of the 9/11 terror attacks, everyone around here is still a little bit jumpy. Feelings are still more than a little raw. We understand you can’t protect everything forever, not in a city as a open and busy and fluid as this one. And here’s the really frustrating part: Most of the things we can think of to do won’t actually protect us against the most likely threats.

You know the ones I mean. A bomb in the subway. Another office-building take-down. Something very scary from the sea or the air. How will X-ray machines at the airport protect us from any of that? How will guest sign-ins in the office lobbies? How will police helicopters in the sky?

They won’t. They can’t. But it’s back to the same old question as we look to the sky in Lower Manhattan: At a time like this one, what else do you have?

Ellis Henican, is a Newsday columnist and Fox News contributor. He is the author of the New York Times bestsellers “HOME TEAM: Coaching the Saints and New Orleans Back to Life” and “IN THE BLINK OF AN EYE: Dale, Daytona and the Day that Changed Everything.”