Nico - I don't think that most Americans are discounting that Iran has some definite capabilities. But, capabilities to do . . . what? Perhaps build a single nuke half the size of what we dropped on Hiroshima?
Think of it like this. Ever look at a praying mantis?
Damn thing looks scary. And, to other animals in its general vicinity and of a similar size, it IS scary!
But, the US isn't an insect. We're the Orkin man. We don't show up at someone's house until we need to. But, if we do show up and you're an insect, chances are really good that you're effed. Sure, we may leave the house a shambles when we leave and not put everything back where it goes - but that's little comfort to all the dead insects laying around.
My point is that Iran and NK can put on all the shows they want. They can test nukes, build fighters, etc. But, their regimes dare not even try to use them against the US. We'd wipe them out.
The only real danger is of a terrorist getting hold of a nuke.