When I say legitimately conducted, I'm talking about not committing war crimes. No targeting civilians, no poison gases, no atom bombs, no cruel and unusual weaponry, no torture of POWs. You know, the bare basics. War is hell, but we don't need to go making super-hell. Regular hell will do.
As for the civilians who are participating in genocide, I say put them on trial. Send them to prison. Civilians are defined by their not posing an active combat risk. If we defeat the IDF and then Bibi picks up a gun, then he's become a soldier. But if he surrenders, then we don't execute him, we put him on trial and send him to prison for life. And it should be a decent prison with a nice quality of life, because there's no need to punish people when they've already been removed from society and can't do anything to hurt people anymore. I'm a supporter of luxury prisons, they have a better rehabilitation rate and I don't believe in punishment,