I spent the past two years with the Guardian Group crisscrossing Europe, from London to Kyiv, assessing security threats to Jewish communities in Europe, which are facing a rise in anti-Semitism. Never did I ever expect my hometown to experience a similar spasm of anti-Semitic attacks, many of them violent. Yet, with 10 reported anti-Semitic incidents over the past week, plus the horrific attack in Jersey City in early December, we must confront this particular hate forcefully. The question is: What can be done to protect the Jews of greater New York?

An effective multipronged response needs to involve the Jewish community, in all of its diversity, and the greater public, as well as city and state governments.

As a former director of intelligence analysis at the New York City Police Department, I can tell you that deterrence is crucial. Would-be assailants need to be dissuaded from carrying out attacks. In recent days, the mayor’s office has committed to deploying extra law enforcement resources to the most endangered communities, many in Brooklyn. This is a good start, but the commitment must go further. Increased police patrols, the establishment of fixed posts and even the use of undercover officers, dressed as observant Jews, are tactics that should be deployed and sustained for the foreseeable future. Removing these resources after only a short time has proved to be ineffective; incidents return as patrols leave.

And what about when assailants are caught?

Data that I’ve reviewed show approximately a third of the recent anti-Semitic attacks in New York are committed by people with histories of psychiatric problems. The arrest of such a person in a violent attack (hate crime or otherwise) might be considered evidence that he or she has a mental illness, which is likely to result in serious harm to self or others. Rather than being released immediately, those arrested should be formally evaluated to determine whether other intervention is necessary. To be sure, this doesn’t excuse crimes of heinous anti-Semitism but helps further combat a condition under which antisocial behavior like anti-Semitism thrives.