This week the insidious wave of bomb threats made against American Jewish institutions crashed into the Bay Area for a second time, with the JCCs in Palo Alto and San Rafael, as well as the San Francisco office of the Anti-Defamation League, receiving calls and evacuating their premises.

Though, as with 100 other bomb threats called in to Jewish institutions over the last six weeks, these turned out to be hoaxes, we are left with two overriding responses: alarm and defiance.

Alarm, in that these bomb threats, along with Jewish cemetery desecrations in St. Louis and Philadelphia, and an apparent shooting into an Indiana synagogue, seem to portend a hyperaggressive new strain of anti-Semitism unlike any we have seen here in decades.

How long before these acts mutate from vandalism to physical assault or murder?

In our editorial last week, we excoriated President Trump for his seeming evasion of an unequivocal denunciation of this wave of anti-Semitic hate. We were then pleased by the president’s statement in his Feb. 28 address before Congress, in which he opened with the strong condemnation we had been waiting for. “We are united,” he said, “ in condemning hate and evil in all its forms.”

That unity certainly embodies the American Jewish community, which, though unnerved, stands defiant in the face of that evil.

In an op-ed earlier this week, San Francisco State University professor Marc Dollinger describes the historic role played by Jewish community centers in this country, calling them “the embodiment of American pluralist democracy, a place where people can congregate and socialize while still respecting the import of their religious and cultural differences.”

They embody the best of who we are, Amy Tobin, CEO of the JCC of the East Bay, reminded us in an open letter to the community: “This is an opportunity to work for our shared values: freedom, safety and equal rights for all … our community will not be intimidated by hatred.”

Similarly, Leslee Adler and Nate Stein, senior leaders of the Addison-Penzak JCC in Los Gatos, wrote to their community that they are “doubling down on our purpose of enriching lives, building community and inspiring Jewish journeys.”

The JCC is a potent symbol of the success and the welcoming spirit of the American Jewish community, and it will remain so. We declare that we will not allow this latest example of anti-Jewish hatred to leave us bowed. And we believe with a perfect faith that an overwhelming majority of Americans stand with us.