Let me tell you what will happen if Iran is REALLY attacked by US. Iran will immediately block the straight of hormuz and that means,
price of oil will rise to $2000 within a few hours. This will cause a massive devaluation of US$ and together with it, all currencies worldwide. The whole worldwide economy will collapse immediately because without oil, there will be riots in US and elsewhere. And remember, in US, there is no gun control.
This is why the US establishment does not want to attack Iran, but Israel does and is pressurising US. Now what Israel wants that is another matter altogether.