Sadly this validates the theory of Russian generals that Russia can launch a massive nuclear attack on UK with impunity.
In my opinion, Russian generals should know that American experts know that citizens of Serbia, Bulgaria, and Greece are as valuable to Russia as Russia's own citizens.
Imho, we should distinguish between a Russian nuclear attack on GB vs a massive Russian nuclear attack on GB; a response to the latter would likely end humanity on this planet.
The 13 day conflict in 1962 over Soviet missiles in Cuba is the closest the world came to a full-scale nuclear war during the Cold War period.
40 years later a conference in Havana revealed how a Soviet submarine armed with a 15-kiloton nuclear torpedo nearly used that weapon on US aircraft carrier.
If that carrier had been destroyed in 1962, perhaps the leadership on both sides would have agreed upon a single US nuclear retaliation on a Soviet military asset of equal value; or not.
I remember this event from my childhood, and I don't see leaders in DC or Moscow today with the same stature as JFK or Nikita Khrushchev in 1962
Cuban Missile Crisis - Wikipedia
"What may have been the most dangerous moment in the crisis was not recognized until the Cuban Missile Crisis Havana conference in October 2002, which marked its 40th anniversary.
"The three-day conference was sponsored by the private
National Security Archive,
Brown University and the Cuban government and attended by many of the veterans of the crisis.
"They learned that on 27 October 1962, a group of eleven United States Navy destroyers and the aircraft carrier
USS Randolph had located a diesel-powered, nuclear-armed Soviet Project 641 (NATO designation
Foxtrot) submarine, the
B-59, near Cuba.
"Despite being in international waters, the Americans started dropping practice
depth charges to attempt to force the submarine to surface.
"There had been no contact from Moscow for a number of days and the submarine was running too deep to monitor radio traffic, so those on board did not know whether war had broken out.
"The captain of the submarine,
Valentin Savitsky, had no way of knowing that the depth charges were non-lethal 'practice' rounds, intended as warning shots to force him to surface.
"Running out of air, the Soviet submarine was surrounded by American warships and desperately needed to surface. While surfacing, the
B-59 “came under machine-gun fire from..."