Israel's threatening to kill 10,000,000s of people - Will the world stop them like we did the Nazis?

At this point it is all political posturing. Threats and counter threats. Each is hoping the other will back down. We did the same thing with the USSR in the 50's through the 80's. I wouldn't get too worked up about it. Nobody in their right mind is going to initiate a nuclear war any time soon.