American policing today is in a state of slow-motion collapse, struggling mightily to attract new officers — no matter how low standards are dropped.

Under sustained assault by the City Council, pundits and self-styled civil-liberties advocates, a new generation of New York City cops is being conditioned to avoid showdowns with civilians, especially where coercion or force is called for. We could have saved the costly investment in body cameras by explicitly telling the cops two words: “Do nothing.”

Officers who do more engagement than what is absolutely required have been threatened by HQ that they’ll find themselves on a list of “troublemakers.” Thousands have, or will soon, head for the exits, telling all within earshot to avoid police work as a career.

In many parts of the country, the police have gone to ground.

Racked by gun violence and pervasive fear, Detroit managed to get through 2016 without police shooting anyone — even as murders continued to rise. Police paralysis is great news for the elite critics of the cops but terrible news for the people dragooned in that town — it likely signals that the police are taking the long and winding road around trouble of all kinds.

In Chicago, the street cops’ ethos is “go fetal, stay fetal.” In Philadelphia, as murders soar, cops are the ones in prosecutors’ crosshairs. It is crystal clear what was long suspected: Costly Justice Department intervention in local police departments expedited the end of hands-on policing.

Uncounted millions are being spent on “community policing” — where officers socialize with a relatively tiny cohort of community residents, some seeking improper benefits from the relationship — when a lot of that money could be better used on enhanced overnight and outer-borough patrols, reducing response times and better training officers to diagnose and handle the 5 million calls that pour in to the NYPD each year.

After all, most serious crimes in New York go unsolved, as they do throughout the nation. We must resist the trap of presentism — conditions at present are acceptable and will be thus so in the future.

Rearranging policing so that it revolves around fault-finding is going to have grave consequences in communities where the police are needed most. But all over the country, policing is now about avoiding all but the most essential, life-and-death interactions.

Two recent videos of public officials being pulled over, one in New Jersey and the other in Baltimore, were seen as triumphs for the officers who remained calm and professional in the midst of a shower of abuse and name-dropping.

The truth, however, is that the proliferation of video recording of cops’ every interaction only will increase officers’ timidity. That will look like self-restraint in some cases, but overall it’ll put law enforcement on the defensive and dull cops’ instincts.

String together a series of adversarial videos, and almost every officer can find him or herself fast-tracked to trouble.

The new-era calculation for the police is: Conflict is the quickest path to extinction.

Some of this was wholly predictable when people who harbor disdain for the police and resent law enforcement are allowed to pose as reformers.

Without a debate of any kind, they have been able to tear down the institution of American policing across the country. Scratch the surface in trendy, uber-safe New York neighborhoods and you will hear public safety and disorder concerns from more than a few. Aggressive panhandling, unreported petty and retail thefts, noise and disorder complaints and a feeling of insecurity on mass transit accompany complaints by those in public housing and poorer communities that violence is never too far away.

There’s no denying that aggressive policing has led to abuse. But often overlooked in the debate was that it was an accomplishment to have police departments where cops patrolled with windows rolled down, engaged those who imperiled community safety and serenity, and where those bent on harming others were forced to look over their shoulders. This era of policing, cops grappling with festering issues, replaced the 1970s and 1980s police paralysis that saw millions leave cities behind as officials themselves acknowledged they were unable to protect their citizenry.

The result of all this is that policing is hurtling to a whole new, uncharted and largely unchosen place. One thing we know from the past is that whether dealing with terrorism or day-to-day issues of crime and disorder, blindly depending on hope can have dangerous, even devastating consequences.

Eugene O’Donnell, a former NYPD cop, is a professor of law and police studies at John Jay College of Criminal Justice.