However, there are some ideas, how to use exiting nuclear stockpiles to cause more damage and trigger a larger global catastrophe—one is most discussed is nuking a supervolcano,
Absurd. Why would anyone do that?
retaliation attack on US may include attack on the Yellowstone, but I don’t know if it is a part of the official doctrine.
Future nuclear war could be using even more destructive weapons
Even the most destructive historical weapons (e.g. Tsar Bomba) have not been deployed. Warheads have gotten smaller over recent decades. No reason for this trend to reverse.
I’ve read that US has an instrument to attack hardened underground facilities by multiple heavy nuclear strike in one place, which allows creating much deeper crate than a single nuclear explosion and destroy targets around 1 km deep. The same way an volcanic caldera cover could be attacked, and such multiple strikes could weaken its strength until it blow up by internal pressure—so you don’t need to go through the whole caldera’s cover. no new weapons for it is needed—just special targeting of already exiting.
Absurd. Why would anyone do that?
I’m sure it isn’t. Also, scientifically speaking it doesn’t even seem possible to ignite a supervolcano with nukes: https://www.iflscience.com/environment/what-would-happen-if-a-nuclear-bomb-was-dropped-on-yellowstone-supervolcano/
Even the most destructive historical weapons (e.g. Tsar Bomba) have not been deployed. Warheads have gotten smaller over recent decades. No reason for this trend to reverse.
Theoretical reasons for Doomsday weapon was laid by Herman Khan in “On Thermonuclear war”. I scanned related chapter here: https://www.scribd.com/document/16563514/Herman-Khan-On-Doomsday-machine
The main idea is that it is ideal defence weapon, as no body will ever attack a country owning such a device.
The idea of attacking the Yellowstone is discussed very often in Russian blogosphere (like here https://izborskiy-club.livejournal.com/310579.html), and interest to the geophysical weapons was strong in the Soviet Union (details here: http://nvo.ng.ru/armament/2006-04-21/6_weapontheyfear.html) - this interest ended up in creating Poseidon artificial tsunami system which is now under testing.
I’ve read that US has an instrument to attack hardened underground facilities by multiple heavy nuclear strike in one place, which allows creating much deeper crate than a single nuclear explosion and destroy targets around 1 km deep. The same way an volcanic caldera cover could be attacked, and such multiple strikes could weaken its strength until it blow up by internal pressure—so you don’t need to go through the whole caldera’s cover. no new weapons for it is needed—just special targeting of already exiting.
Russian Poseidon system has 100-200 Mt bombs delivered by a very large torpedo and is in final stages of construction. https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_System