Iran might have 1 or 2 but we have hundreds iran doesn't want us to get MAD also known as Mutual assured destruction there desert country would be irrataded for the next 100 years where as NORAD would of stopped there missile over flying over the Pacific or Atlantic ocean
I pictured a mentally deficient trucker, ala Curt Russell in Big Trouble in Little China, but fatter and uncool screaming into his phone while Real American by Rick Derringer plays in the background.
The point of building nukes isn't really to launch a nuke at someone, it's to make others decide that attacking you is too risky. Missile defense isn't perfect, so even if it probably would stop them, there's still a risk one gets through, that someone would have to take into consideration before launching an attack. It's even more a threat against Isreal, since they have less time to intercept, and even one missile getting through would destroy a comparatively larger fraction of the country, being that it's fairly small.
Japan was nuked at a time when the realities around nuclear weapons (namely, the hostile nation having them too, or an ally of theirs) were different. The strategy around them is dramatically different now from then.