[Goose]

Thanks for the gifted article. 

One thing I did not see addressed in the article is the step going from "we have a nuclear weapon" to "we have a nuclear warhead that fits on a ballistic missile"

My impression is going from one to the other is far from trivial. If so, there would still be a window where they lack a viable delivery system needed for deterrence and could prompt an even more vigorous response to prevent them from acquiring one.

Good points. The sequence is actually a bit longer. It goes from "We have a nuclear weapon" to "We have a nuclear weapon that we have tested and it worked" to "We have a nuclear weapon that we have tested several times and it works reliably". A declaration of "We have a nuclear weapon" could be a total bluff. Such a declaration would indeed prompt (and justify) a more vigorous response from Israel and possibly others. It makes no sense for Iran to make such an announcement unless sheer desperation drives them to attempt deterrence in this manner. Once Iran has detonated a nuclear device (which would be detected by Israel and lots of others), then they are officially a "player", although still minor league. Setting of a device underground once doesn't mean a nation can reliably build a functioning device. North Korea demonstrated that early on with its squib detonations.  However, it does mean that nation can do it once, which may be enough.
 
Building a bomb that can ride on a ballistic missile is indeed a separate step and would not be easy starting from scratch. Iran probably has access to lots of information from other countries (probably Russia, perhaps others) on how to do this. Unlike the US efforts in the 1940s Iran would ab initio design/build a bomb that was appropriate to their intended delivery vehicle. However, Iran doesn't need to use a missile. They could smuggle the bomb into Israel and drive a truck to where it will be detonated. They could also carry the bomb on a civilian airliner or ship. All these alternate methods have risks associated with them, but what is Israel's risk tolerance? What is Iran's, and what are Iran's alternatives if they are in extremis? A sub-critical detonation would result in a "dirty bomb". How would Israel respond to that, given that Iran possibly has another 9 (or so), some of which may actually go off? It is a very unpredictable situation.
 
The problem for Iran has always been that even if they have a fully functional deliverable bomb using it against Israel is presumably signing their own death warrant and that of millions of Iranians. Iran probably isn't that crazy. The fear always was they would give a bomb to somebody like Hamas, who would actually use it. Israel would then be faced with the fact wiping out Gaza would be cold comfort for Haifa or Tel Aviv. It would be the classical "crazy man" usage of nuclear weapons. Iran could then say "It wasn't us" and hope to avoid destruction. Probably wouldn't work, but maybe it would be attempted.

[Goose]

Thanks for the gifted article. 

One thing I did not see addressed in the article is the step going from "we have a nuclear weapon" to "we have a nuclear warhead that fits on a ballistic missile"

My impression is going from one to the other is far from trivial. If so, there would still be a window where they lack a viable delivery system needed for deterrence and could prompt an even more vigorous response to prevent them from acquiring one.

Good points. The sequence is actually a bit longer. It goes from "We have a nuclear weapon" to "We have a nuclear weapon that we have tested and it worked" to "We have a nuclear weapon that we have tested several times and it works reliably". A declaration of "We have a nuclear weapon" could be a total bluff. Such a declaration would indeed prompt (and justify) a more vigorous response from Israel and possibly others. It makes no sense for Iran to make such an announcement unless sheer desperation drives them to attempt deterrence in this manner. Once Iran has detonated a nuclear device (which would be detected by Israel and lots of others), then they are officially a "player", although still minor league. Setting of a device underground once doesn't mean a nation can reliably build a functioning device. North Korea demonstrated that early on with its squib detonations.  However, it does mean that nation can do it once, which may be enough.
 
Building a bomb that can ride on a ballistic missile is indeed a separate step and would not be easy starting from scratch. Iran probably has access to lots of information from other countries (probably Russia, perhaps others) on how to do this. Unlike the US efforts in the 1940s Iran would ab initio design/build a bomb that was appropriate to their intended delivery vehicle. However, Iran doesn't need to use a missile. They could smuggle the bomb into Israel and drive a truck to where it will be detonated. They could also carry the bomb on a civilian airliner or ship. All these alternate methods have risks associated with them, but what is Israel's risk tolerance? What is Iran's, and what are Iran's alternatives if they are in extremis? A sub-critical detonation would result in a "dirty bomb". How would Israel respond to that, given that Iran possibly has another 9 (or so), some of which may actually go off? It is a very unpredictable situation.
 
The problem for Iran has always been that even if they have a fully functional deliverable bomb using it against Israel is presumably signing their own death warrant and that of millions of Iranians. Iran probably isn't that crazy. The fear always was they would give a bomb to somebody like Hamas, who would actually use it. Israel would then be faced with the fact wiping out Gaza would be cold comfort for Haifa or Tel Aviv. It would be the classical "crazy man" usage of nuclear weapons. Iran could then say "It wasn't us" and hope to avoid destruction. Probably wouldn't work, but maybe it would be attempted.