You act as though Israel is in control. Israel will do what America says if America tells them what to do because their country is 100% dependent on it.
If America told them we will stop selling arms to you and give you the South Africa treatment if you carry on, then they wouldn’t act. And if they did they wouldn’t last long as a nation.
Somehow America has forgotten that they are the ones in charge of them not the other way around.
Israel launching a nuke would likely be the death of the country. Any public support the west has would die off and they would become completely isolated. That is a red line that cannot be tolerated by anyone.