Orbital nukes are hardly high ground. With a high resolution radar it is easy enough to find anything you want in orbit, more so to detect something on a sub-orbital trajectory (hmm, I seem to recall a bunch of radars built over half a century ago that could do that). Try that against an SSBN hiding somewhere in the Pacific/Atlantic/Indian/Arctic, it's a bit harder to do. Practicality and survivability ranks nuclear weapon satellites somewhere below air breathing bombers, hardened silos, land/air mobile platform and submarine based systems.
"High ground" encompasses more than just nukes. To quote myself:
I am in favor of "going back to the moon" or elsewhere insofar as that is a military-themed and purposed effort. Will it give America a leg up militarily? Can we monopolize space-based military power? Will it allow us to treat the treat of the solar system as our new frontier? Can we implement a "Monroe Doctrine for the Solar System?"
Nukes on sats is likely the
least significant use of military power in space, mid to long term.
But, in hte interests of debate....
Oh, I agree that finding planes & subs would be
much more challenging. But, "seeing" a satellite on radar and IDing it as a nuke-toting threat are two different critters. Even if we got visual ID on some satellite we thought toted nukes, we very likely wouldn't blast it out of the sky, especially when the Chicoms/Russkies/Norks/etc. are claiming it is a "100% peaceful scientific research satellite designed to save fluffy puppies and children."
Nuke weapon satellites don't have to survive any more than the booster section of an ICBM has to after it has released its warheads. Just drop their ordnance. After that, they are expendable.
Also, there is the small problem that we have very,
very few missiles capable of reaching & killing satellites. The ASAT missiles we tested back in the 1980s nailed satellites upwards of 550KM and the Chinese nailed one at that altitude in 2007. The SM-III can't get that high. Back in 2008 it had to wait until the dying satellite was low enough (~150KM) for it to take a stab at it. About the only ones on hand are the GBIs that are part of the National Missile Defense, and those are located to intercept ICBMs mid-phase. They might not be too useful in downing satellites over CONUS before the sats can release their warheads. Some sats are in orbits higher than any country has successfully nailed a satellite.
It looks like we can (conservatively) wring out upwards of 1 megaton for every thousand pounds of warhead, given old-tech W53 (9 megaton/8000lbs) warheads. I bet the USSR and China have achieved that level of efficiency in the 50 years since we developed the W53. Given that the Canadians have launched a 6 ton / 12,000lb satellite, that is a whole lot of nuclear destruction.
Anyways, it is interesting to think on the topic. If you have more data, do please share it.