Honestly, I am 99% sure (4) would be fine - if Russia’s nukes are anything like their conventional forces, they’d likely never launch succesfully anyway. And Putin knows what happens to Russia - and to him - if he tries it. That said, the costs of being wrong are really really really high, so as long as (2) and (3) are working, and they seem to be, no need to go to (4) right now.
Russia certainly has questionable maintenance when it comes to their military, but I suspect of all things, nuclear ICBM maintenance is the least likely to be skimped on. Russia also learned their lesson with submarine quality and maintenance long ago, now making very capable machines. Ballistic submarines are easily the most destructive weapon ever made. And I certainly would not underestimate their missile technology, its among the best- in a lot of cases better than our own.
Heck, for the past 20+ years American Atlas III and V rockets having been using Russian RD-180 engines (Ironically these Atlas family launch vehicles are derived from Atlas ICBMs created to destroy Russia). These engines use oxidizer rich staged cycle (aka closed cycle) combustion. I’ll spare the technical discussion but will say there are huge technical hurdles and American engineers in the 90’s thought this engine design was
impossible and literally did not believe the Russians had the technology working let alone the performance. The RD-180’s were 10% more efficient than similar open cycle engines, which is huge. In fact Russia had been using oxidizer rich staged cycle engines since the 1950’s.
In the Cold War the US focused on global power projection and air dominance, while Russia focused on missiles and air defense. The US had the benefit of launching attacks from Europe, but for Russia to attack the US, ICBMs were really the only practical solution. To defend from NATO aircraft, surface to air missiles and accompanying radars were heavily invested in. Such tech was less of a priority for the US.
Russia also had to have a weapon to destroy aircraft carriers i.e. the P1000 anti-ship missile found on the Moskova- 1000lb conventional (or 350kt nuclear) warheads with a range of 350-500 miles at Mach 2.0. We don’t have anything close. Plus, since the 1970’s(!) their anti-ship missiles automatically coordinate attacks with each other- I’m not even sure we have such a system today.
Anyways, when they have 6000 nuclear warheads total and 1500 deployed, many could fail and yet there would still be plenty to destroy whatever countries they want.
That said, I’m not too concerned about nuclear war. I’d be more concerned about chemical weapons. I believe Russia is only boasting about their nuclear weapons to try to intimidate the West, which honestly worked to some extent particularly in the beginning of the war. Our media is obsessing about it primarily because they have nothing else to talk about and fear sells.
Secondly, I think Putin is sensible enough to know if he uses nukes In Ukraine the world will not standby and much of his population may not be happy with him risking a global nuclear war. At best the entire world except Iran and North Korea cut all ties with Russia and they become essentially West North Korea.
Third, Putin could order a nuke but there’s a whole chain of command to carry out the strike. I think it’s very possible his generals would refuse, not to mention others responsible for carrying out the strike. There have been multiple cases on the Soviet and US side where due to errors false threats were perceived and nuclear strikes could have been and almost were made… but the person with their hand on the trigger refused.
