Zionists, Jewish & Christian, don't believe Israel's war on Gaza to be genocide because they consider any detraction to be anti-Semitic propaganda even if Israeli groups like B'tselem, associated Israeli or Jewish groups, or even the verbatim words of Israeli politicians and media figures expressing genocidal intent in very obvious terms and statements.

It's telling that when Dershowitz was confronted with one of the ICC prosecutors being a Jewish holocaust survivor that Dershowitz dismissed him not as anti-Semitic but as merely mistaken.

It is unsaid but very obvious, that Israeli politics revolve around the notion that the existence of Palestinian people in their historic homeland is anti-Semitic, and therefore worthy of annihilation by violence or displacement.