BERLIN — To judge by the outpouring of comments from politicians and writers and from the newspaper and magazine articles in response to the Nobel laureate Günter Grass’s poem criticizing Israel’s aggressive posture toward Iran, it would appear that the public had resoundingly rejected his work.

But even a quick dip into the comments left by readers on various Web sites reveals quite another reality.

Mr. Grass has struck a nerve with the broader public, articulating frustrations with Israel here in Germany that are frequently expressed in private but rarely in public, where the discourse is checked by the lingering presence of the past. What might have remained at the family dinner table or the local bar a generation ago is today on full display, not only in Mr. Grass’s poem, but on Web forums and in Facebook groups.

One word has surfaced consistently in such discussions: “keule,” which means club or cudgel. The charge of anti-Semitism aimed at Israel’s critics — and in the case of Mr. Grass, by bringing up his past as a member of the Waffen-SS — is widely viewed as a blunt instrument that silences debate, and in the process prevents Mr. Grass from making a point about the dangers of a first strike by Israel against Iran over its disputed nuclear program.