In the wake of the San Bernardino massacre, a landmark study on how American Muslims become radicalized is at risk of . . . being suppressed.

That study has been available on the NYPD’s Web site since 2007, but the city may be about to scrub it to settle three lawsuits over supposed civil-rights violations by the department’s anti-terror work.

Team de Blasio has until Friday to file legal papers indicating how it wants to proceed on one case, but lawyers have reached a deal “in principle” on two others — though details aren’t yet public.

You couldn’t ask for worse timing.

As a poll last week showed, terrorism today is a top issue for more Americans than at any time since 9/11 — with nine out 10 fearing an attack by someone living here.

So why — at a time of increased focus on homegrown radicalization — would the city intentionally suppress information about the radicalization process?

The plaintiffs in the lawsuits — including three Muslim leaders and two mosques — claim the NYPD’s “Muslim mapping” initiative was illegal. In that program, the NYPD sent agents into public areas of Muslim communities as part of its counterterror efforts.

Commissioner Bill Bratton scrapped the program, but plaintiffs reportedly also want the radicalization report purged from the Web site and its records deleted. Plus yet another court monitor to oversee the cops.

Let’s be clear: The city was never guilty of anything in the suits, and Mayor de Blasio would be wrong to make concessions.

But yanking a report that contains key ­anti-terror info and deleting relevant data — at a time like this — is beyond nuts.

Who, besides terrorists, their backers and wacky civil-liberties extremists, would want to do this?

The ACLU, a party to one of the suits, in 2013 actually mocked the idea of radicalization, calling it “a widely debunked” concept and comparing it to a “villain in a horror movie.” Tell that to the families of the 14 dead in San Bernardino.

And why would any mayor agree to it?

The report offers valuable insights into the mindset, motivation and methods of Muslims who turn jihadi. Others studying these issues, including at the Congressional Research Service, have relied on it.

If the city is foolish enough to try to hide the report, rest assured: New Yorkers will still be able to find it — at nypost.com