We got lucky

Change just one variable, and what transpired Monday morning in an underground passageway connecting Times Square subway station and Port Authority Bus Terminal would have left the city not just shaken but horrifically wounded. As it happened, the 27-year-old man who tried to set off an improvised explosive device saw the device malfunction. He sustained serious injuries and three other people in the immediate vicinity were hurt, none seriously.

Had the bomb detonated as intended, it would likely have killed by the dozens — likely even more had it gone off on a crowded rush-hour platform, or on a packed subway car, or on a bus.

And if Port Authority police had not rushed to apprehend the terrorist moments after that initial fizzle, he could well have set it off on a second attempt and done terrible damage after all.

Have no doubt: Fellow followers of ISIS who will consider Akayed Ullah’s attack a missed opportunity are taking notes. Adjusting strategies to terrorize more capably next time.

So do not feel debilitated or be terrorized. But, understanding that New York long has been and remains the planet’s top terror target for radical Islamists, and that our sprawling subway system is vulnerable by defintion, be ever on guard.

Most of the work of preventing the next attack rightly falls to professionals, and New York City is blessed with the best.

The NYPD’s intelligence and counterterrorism professionals, working with their partners at the FBI, must continue to do what they already do with tirelessness, creativity and skill: find the corners where would-be terrorists are radicalized, where they plot, and stop them before they strike.

Federal officials dare not cut a red cent of vital counterterrorism funding that flows to New York City. President Trump tried doing that earlier this year, proposing a budget that would slash a program paying for urban terrorism prevention and response from $605 million to $448 million. Get those funds off the chopping block. Now. Monday’s terrorist was from Bangladesh, not among the nations included in President Trump’s sloppy travel ban.

More importantly, he had been in the United States for seven years. He was radicalized here.

We will not prevent the next attack, one that may be the genuine stuff of New York nightmares, by closing the nation’s ports and gates.

We will do it by making targets like the transit system less vulnerable in every way possible, without limiting the free flow of people in and out.

Diving deep into the ever-more-shadowy recesses of the internet where radicals congregate.

And developing ever-better sources inside New York’s Muslim community — through collaboration, not confrontation.

We must do everything in our power to stop the killers — everything short of changing the very character of the city that makes it, for them, a target. That is nonnegotiable.