Phil Ochs wrote a song about this, "The Scorpion Departs, But Never Returns"[1].
An entity capable of executing that recovery operation is capable of making their own, buying one from a less savory nation state, etc.
In fact, I wouldn't be surprised if someone hasn't already taken it, and left a dummy weapon in its place.
Sure, deep sea exploration by humans is hard... But using unmanned craft, they're mostly impervious to pressure.
For a non-nuclear nation, that would be all they'd need to become a nuclear nation.
Then blow it up in a test explosion to show the world, and then they could work slowly on making another bomb while bluffing that they have lots ready to go.
Two in this list were from accidents on aircraft and submarine with tactical nuclear weapons. Tactical nuclear weapons weren't removed until later.
Most of them are in deep water so recovery alone would be a nigh insurmountable task, they all have been sitting in salt water corroding for 65+ years, and they all have been radioactively decaying for the same period. You'd be remanufacturing them from scratch essentially, and probably could have come by the materials with the same budget that the recovery operation would cost.
https://en.wikipedia.org/wiki/1965_Philippine_Sea_A-4_incide...
"The attack jet fell over the side during a training exercise while being rolled from the number 2 hangar bay to the number 2 elevator. The pilot, the aircraft, and the B43 nuclear bomb were never recovered from the 16,000 ft depth."
Imagine if the practice nukes armed with an “ARM” command, but the real ones expect “ARM\n”… that kinda stuff.
Hadn't really know about that, and I thought I knew lots of stuff about the Cold War.
Also, the Kursk incident that happened ~30 years later and which resulted in approximately the same number of victims (118 vs 99 for the Scorpion) was presented by the Western press as this cataclysmic event for Russia, an event that was proving that the Russian State was of no good, structurally speaking. For comparison, apparently the only thing that the West managed to create about the Scorpion sinking was a song, not even a Hollywood B movie.
1956 - B-47 ran out of gas over Mediterranean.
1958 - B-47 having difficulty to land jettisoned somewhere near Wassaw Sound near the mouth of the Savannah River so that it wouldn't crash with a nuclear bomb bon it.
1961 - B-52 crashed shortly after taking off. Most of it was dug up. (Dr. Jack ReVelle obituary from Jan 2023 - https://www.ncrabbithole.com/p/jack-revelle-goldsboro-nc-bro... )
1965 - A-4E rolled off the deck of the USS Ticonderoga into the Pacific Ocean near Japan (Japan wasn't happy about it)
1968 - USS Scorpion attack sub sank somewhere near the Azores Islands.
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This isn't a "hey, there are a bunch of nukes out there in the hands of (more) irresponsible people."