Meanwhile,
there are some details of Russia's "retribution strike" that it inflicted immediately after the sabotage of pro-Ukrainian militants in the Belgorod region with hostage-taking.
The Russian hypersonic missile "Dagger" with a target hitting speed of Mach 12 (12 times the speed of sound) managed to hit the joint Ukrainian-NATO command and communications center installed at a depth of 130 meters!
The underground headquarters (built at a depth of 400 feet) housed several NATO officials and reportedly housed over 300 people.
Of course, we will never know the details of the incident, because no one recognizes the presence of these NATO officials in Ukraine at that moment.
I remember when the U.S. made Saddam's face puff up and ears bleed by doing some things on one of his bunkers. They didn't get him, but made him look funny with weird glasses for a while.
I'd imagine that very synchronized and precisely spaced hits with three or more missiles could produce a very localized effect deep under the ground. Essentially similar in concept to what they are doing with beam forming on the electromagnetic spectrum. No nukes needed. Just good intel.