Israel's war against Hamas was not a genocide. (Nor was it a distinct war, but merely part of the much longer war against the Palestinian people.)

Israel's war against Hamas was part of a campaign of genocide against the Palestinian people that has been conducted through much of that longer war, a campaign that it started decades before Hamas existed (and fostered the creation of Hamas, during the more intense period of its occupation of Gaza, as a tactic to facilitate through both dividing its opposition and making it less internationally sympathetic, as the primary constraint on the campaign has always been international, and particular US, tolerance.)