[Oberon]

Originally Posted by ikalugin

There is no reason to not make Tu95 carrier aircraft unmanned if need be. But yes, decrease in yeild was intentional.

Now that would be interesting, a Tu-95 drone, of course the key factor in it, as in all drones, is the control link. Although given that the target of the Tu-95 isn't likely to move around or change then you probably don't need a control link, just point it at the target and let it go on its merry way.
You'd need air superiority though, otherwise it'll just get eaten by an enemy fighter as soon as it reached the frontline.

I stated that UR-500 was an ICBM (with that specific payload), meaning that it did not boost it's RV into the LEO. There was also UR-700, but that was never built.

Fair point, I didn't take that into consideration. Although it would be a bloody big target for ABMs, but on a sub-orbital trajectory...I guess it could be done. There's also the N1, although that was never really designed as an ICBM. Korolev was a busy man, a smart man too, it was to Russias great fortune that he managed to get released from the gulag and wasn't executed by the NKVD during the purge. I've had the fortune to look at a few of Russias space objects close up, including Valentina Tereshkovas (who turned 80 the other day, Happy Birthday!) Vostok 6 capsule and the Voskhod 1 capsule, as well as the LK-1 lander test unit. It's a shame that after the Apollo landings the Soviet Union gave up on trying to get a cosmonaut on the moon.

With the high yeild device there is little difference if you explode it at sea level or at a low depth due to the fireball size.

Again, true, as soon as the bubble breaches the surface it will release the radiation from within it up in the pillar. Obviously though you do reach a point where the depth will be greater than the fireball, with the Tsar Bomba that would be anything deeper than 6 miles, although in that instance even though the fireball itself would be shielded, the bubble would breach the surface, so you'd still get the radiation release.

Turning normal thermonuclear bombs into so called "cobalt bombs" is a matter of adding a jacket. Considering that we view strategic nuclear weapons as a deterent and only as a deterent we would actually welcome change of a precision counter-force potential into broad effects counter-value potential as that would improve strategic stability.

I see where you're coming from there, to make the consequences of using the weapons so dreadful that they'd never be used.
Of course, the ones that you should be concerned about, rather than the more accurate ICBM guidance systems, are the bunker-buster devices, because if a President is going to go nuclear, that's probably the most likely device they'd go nuclear on, especially against someone like North Korea who is found of digging holes. Fortunately, they've fallen out of favour in the US, in line with using standard explosives, but I know that Russia was quite interested in the bunker busting technique and designs because a group of Russian spies were checking it out back in 2010.
The whole point of the nuclear taboo though is the de-normalisation of nuclear weaponry, and I don't think increased accuracy does that. Increased accuracy with an impenetrable defensive shield doesn't do that either, but it does make it seem as though a nuclear war can be 'won', but even then I think that only 'General Rippers' would be tempted to launch a first strike, but I can understand Russias desire for insurance.
That being said, the Oscar-IIIs are going to have to dampen their sound signature by a lot or have a constant escort otherwise what's to stop the US assigning a Virginia SSN to every Oscar-III it can find and then blowing the thing out of the water as soon as war is declared?

Still, while the US has not officially declared a 'No First Use' policy, the 2010 review did assure that ""The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations." So I think Russia can rest easy there, still...Доверяй, но проверяй as they say.

Morever if push comes to shove we would probably benefit relatively with increased global fallout due to the superior shelter, reserves and post attack reconstruction.

Perhaps, again though it comes down as to whether a nuclear war can be 'won'. I mean your major cities have shelters, what about the small villages and towns? The farming communities? The reserves will last a while, but can they last over a century?