No need to annihilate, just inflict unacceptable damage & destroy nuke sites. That's why Trump recently met Kim & both hope to meet again. The MAD doctrine time is over. Also precision non-nukes can substitute for tactical nukes.
Yes MAD doctrine time is over. Now the possibility of using a nuclear weapon is increasing. Another START increases only the risk. Russia is currently unable to cover all military purposes in the US and where the NATO regime. On the other hand, the potential of the UK and France, 8 SSBN, comes to the USA.
No, you are both wrong... MAD is the only thing holding the US back... it is only the threat of destruction of the US that stops them because otherwise war is good for their economy.
Yes, the need is to kill people... Russia doesn't need to hit US ICBM silos, or their air bases... they will be empty by the time Russian weapons get there whether the US starts it or Russia does.
The purpose of Russian strategic weapons is to clear a path to launch positions for their strategic bomber cruise missile carriers... so radar and airfields in north america are all targets as well as ABM systems and of course population centres.
Precision guided weapons have replaced nukes in theatre war, but not strategic war... in strategic war you don't need to hit silo hatch covers because by the time your missiles reach there they will be empty... cruise missiles will be aimed at cities and food production areas, and water supplies... they are "you've killed us so we are going to kill you" weapons.
With NATO bases so close to Russia there is a risk that a large conventional precision strike could take out enough systems to stop a retaliation strike to take place... a sort of pre-emptive decapitation, except that currently Russian air defences can probably cope with western cruise missiles and Russian forces are too strong to get away with it... a Russian nuclear strike would be launched as soon as it was clear that was what NATO was trying to do... and it becomes a case of use it before you lose it (ie ability to launch nuclear strike).
For there to be a new Start agreement signed that replaces the existing agreement there will no doubt need to be a lot of changes... the US will want to include hypersonic missiles of course, and Russia will likely demand more missiles than the US because the US also has UK and French missiles on their team... not to mention the US controlled ABM system in Europe, in the US, on AEGIS class ships, and likely soon in Japan/South Korea.
I rather suspect the Russians wont be under any illusions and will play rather more hard ball than they have done before.
The whole point of START is to maintain MAD... and various weapons like Poseiden and the nuclear powered cruise missile should offer a guaranteed revenge for Russia no matter who starts what.