[Dragon]

The problem with tactial weapons is getting good enough at making weapons at all to even think of miniturizing the technology.

That's pretty much what he said. It's not like it's impossible to make a nuke that small, but to make an effective tac nuke one needs to have a good deal of experience and technology in making nuclear weapons, which Iran doesn't have. It took almost 20 years to go from Little Boy to B57, and this was the US nuke program with top scientists of the world, astronomical budget and no international organization breaching down it's back and trying to take the program down. I don't see Iran building such a nuke in the near future, and it's unlikely they'd be able to get them from abroad.

[headdie]

The problem with tactial weapons is getting good enough at making weapons at all to even think of miniturizing the technology.

That's pretty much what he said. It's not like it's impossible to make a nuke that small, but to make an effective tac nuke one needs to have a good deal of experience and technology in making nuclear weapons, which Iran doesn't have. It took almost 20 years to go from Little Boy to B57, and this was the US nuke program with top scientists of the world, astronomical budget and no international organization breaching down it's back and trying to take the program down. I don't see Iran building such a nuke in the near future, and it's unlikely they'd be able to get them from abroad.

there is a small difference though, because of the American and Russian nuclear programs Iran now have an idea of what is generally possible and can better target specific research goals meaning they can avoid some of the dead ends that the original programs no doubt went down which will save some development time and resources.  Also the American and Russian physicists were literally writing the book on nuclear physics as they went along, these principles are much better understood now and taught to a much wider cross section of people, heck from my physics lessons at age 15 I understand the gist of an uncontrolled nuclear event.

[Klaustrophobia]

also, computer simulations/design.  we were building our first nukes with a slide rule.

[Dragon]

It would still be very difficult for the Iran to come up with a functional tactical device in 10 years or so, and that's a generous estimate. The principles on which a nuke is based are simple, but the actual technologies used to make an effective nuke are really complicated and usually classified, meaning Iranian engineers would have to pretty much start from scratch. That goes double for a small, tactical device. And unlike US during Cold War, they don't exactly have access to top engineering teams in the world. While it's true that a large part of the job has been done "for them" during the Cold War, this only makes developing such a device in Iran possible at all. I'd say, they'd need 10-20 years to come up with anything workable in tac nuke department, assuming the whole program survives this long (unlikely, considering everything).

[General Battuta]

Russian and Pakistani know-how is historically often available.

[Klaustrophobia]

i disagree with that assessment (dragon).  the nuclear know-how cat is out of the bag.  that part isn't even classified, it's common academic knowledge.  and "classified" isn't as strong of a thing as people think.  i'd be willing to bet iran already has or can get nuclear weapons data if they want it.  not necessarily ours, but someone's.  discounting willful aid, russia is rather infamous for not keeping a lid on it's nuclear.... stuff.  it is frequently said that the hard part of making nukes isn't designing them, it's obtaining the materials, and we know they are actively pursuing this.  as for the people to make this happen, it doesn't take the absolute best in the world.  you just need them to be competent, and iran undoubtedly has at least a few of those.

[StarSlayer]

Highway to the Ahmadinejad zone!

[NGTM-1R]

As informed as you generally seem to be about these things, you're really not in this instance.

On the contrary. Nukes, like anything else, have steep requirements in machining and engineering technique the smaller you make them. The technology here also has very few other applications. As North Korea will be happy to demonstrate, materials aren't the real problem either: the real difficulty with manufacturing nuclear weapons is developing the precision industrial capacity. Building a small nuke makes that problem much, much worse.

[Dragon]

Russian and Pakistani know-how is historically often available.

Know-how, not blueprints. They'd still have to design the bomb. Also, remember that creating a nuclear device doesn't end at designing the warhead. You also need to develop production lines, machinery and everything that's required to turn a pile of Uranium and spare parts into whatever is on the blueprint. Iran doesn't have precision industry to produce advanced nuclear weapons (tactical weapons among them) in any useful quantity. To make a tactical nuke, you can't use a simple gun type device, since you need to detonate a very small mass of the fissile material. For that, you need the implosion type device which would compress the material into a near-perfect sphere. This has to be extremely precise, and thus the manufacturing process is very complicated and expensive. Iran could probably develop and produce a tac nuke in a science lab, but it would hardly be of any use, since labs are not suited for industrial production of the warheads, and those are not war-ending tools of apocalypse, but simply very, very destructive iron bombs. Having just one wouldn't cut it.

[headdie]

Russian and Pakistani know-how is historically often available.

Know-how, not blueprints. They'd still have to design the bomb. Also, remember that creating a nuclear device doesn't end at designing the warhead. You also need to develop production lines, machinery and everything that's required to turn a pile of Uranium and spare parts into whatever is on the blueprint. Iran doesn't have precision industry to produce advanced nuclear weapons (tactical weapons among them) in any useful quantity. To make a tactical nuke, you can't use a simple gun type device, since you need to detonate a very small mass of the fissile material. For that, you need the implosion type device which would compress the material into a near-perfect sphere. This has to be extremely precise, and thus the manufacturing process is very complicated and expensive. Iran could probably develop and produce a tac nuke in a science lab, but it would hardly be of any use, since labs are not suited for industrial production of the warheads, and those are not war-ending tools of apocalypse, but simply very, very destructive iron bombs. Having just one wouldn't cut it.

I dont know, would you like to be the one deciding to go to war knowing there is a chance that a nuke will be deployed against your forces. 

In the situation where Iran would deploy such a weapon the government would be looking at a situation where they have a good chance of being toppled/killed by the invaders so would have not a lot really to loose.  the invader on the other hand will have to deal with the political backlash from sending troops into a nuke armed country with delivery capacity and the media sensationalism that would surround such an event if deployed.

indeed 1-5 warheads would be enough to stall an invasion by months if not a couple of years while the wider world tries to use political solutions to whatever the days problem is rather than risk the above scenario.  After the described time span the political backing for an armed solution to Iran's actions will have probably dwindled and Iran will have hidden whatever activity it was again.

[Dragon]

I dont know, would you like to be the one deciding to go to war knowing there is a chance that a nuke will be deployed against your forces. 

What I would do would be to send in a DEVGRU unit to blow up their sole nuke just before the invasion. Or find out where they keep it and Tomahawk the place. Or shot down the plane delivering this nuke. There are ways of dealing with such threat. 5 bombs are hardly a deterrent, especially tactical ones. They could be used for political purposes (though I'm not sure if just 5 bombs would accomplish anything), but once actual ordnance starts flying, they'd have a very slim chance of actually doing damage. Considering all that, Iran would most likely focus on developing larger bombs which it actually could produce on a larger scale. They'd have more political power that way and would not be susceptible to being destroyed in a single, daring raid or precise missile strike.