Both sides are in the wrong here. This letter is despicable but Obama doesn't get it about the threat Iran poses, either.
No, Obama gets the threat, but has chosen to go with diplomacy rather than military confrontation.
The UK, Russia, China, France, and Germany apparently agree.
In fact I'd counter that Obama understands the threat far better than these grandstanding idiots and Bibi Netanyahu.
Not to put too fine a point on it, but the threat has been wildly overblown.
The problem is that he's aiming for the best agreement he can get out of them--never mind that it's not going to actually work. Iran has already made agreements with holes in them, they'll just keep playing such games.