And they also have the capability to in a few years have nukes, which WILL cause a ME nuclear arms race, which WILL end up in a shootout. That will most likely not be with Israel (at least initially -- they might get dragged into it, tho'), but with Saudi & friends. Also, IMO, it is more likely the shootout happens once Iran and Saudi are up to Israeli numbers of nukes (which would surely grow too). Small numbers of nukes (and delivery systems) really don't help Tehran much: The Israelis are and the Saudis (with added US and Israeli resources) would be too good at shooting down missiles a few at a time. That capability can be extended to Europe, too. For an Iranian nuclear threat to be really credible, I'd say they need 100 nukes ready to launch, minimum, and by the time they get to that, since their regional enemies won't be sitting still, double it. (This of course ignores "suitcase" bombs and the like, which is a little different matter, but if one thinks it through, such do not put Iran in a good position vs. a well nuked-up SA.)
Iran wants, essentially, a MAD capability vs. Saudi, and then leverage that in much the same way as a suicide bomber: "Give us "X" or we will blow up EVERYTHING.
This is a bit different than the threat from the Norks, where they have Seoul to blackmail, in very short range.
GOPJ, like many, does not seem to understand the implications to US of Iran's current capability (global economic chaos), if unchecked, or later on, the fallout (sort of a bad pun) of a sizeable nuclear war in the ME.
The bottom line. It really doesn't matter that the nukes are exploded in the ME, the radiation will be coming to a neighborhood to you.
Iran's not playing on the 'mighty' playing field - that's the one we're playing on. They're playing on the 'human strategy of the crazies' field.
So your example above about suitcase nukes is important.
Let's say three 'suitcase' nukes go off - two in Israel and one in Tampa. Iranian officials are in a meeting with this President or the next one or the one after that... and the Iranian official turns to the President and says, "there's nothing left of Israel so there's nothing to 'fight over' - AND we have 5 more suitcase nukes in American cities ready to explode - including one in DC if you decide to retaliate. So, Mr. President what's your decision: Peace or millions more dead Americans?
Now, just for the fun of it - let's play on the extreme strategy field for a while and come up with a solution to the above scenario...