NATO would still have a multiple of conventional firepower to defeat Russia few times over. That's based on a scenarios if Russia somehow manages to fire all of its 1000 warheads into NATO force in Europe, without being fired back at.
Sure most Europe falls well under that, but warheads tend to be deployed on solid rocket motors as they're comparatively low maintenance. Solid rocket motors can't be shut off once they're started, so you have very little control over its burn time once its started (this is one of many reasons why the Space Shuttle had so many black zones where an abort would result in the death of the crew). All you can control is its trajectory, but targeting europe, would mean either a very shallow trajectory, relying on air resistance to sufficiently slow the missile at the target, potentially resulting in the missile and warhead burning up or tearing up from g-forces in the lower atmosphere; or an extremely steep trajectory, resulting in, again, either strong g-forces or incredibly high temperatures meaning the missile burns up or tears up in the lower atmosphere.
Given the reluctance toward a first strike, I'm not convinced that russia can strike most counter-value targets in Europe with its fixed deployments. I think of the few missiles it has that can reach europe, they're likely aimed at counter-force locations, with the rest aimed at the significantly larger nuclear force in the US. Its subs are a different question though.
My assumption would be that any Russian missile boat is being trailed with an opposition attack sub just waiting for it to become a sitting duck while prepping for launch operations.
Also, the whole premise of warheads burning up on reentry is a bit ridiculous. Notice how the most recent North Korea test had an extremely steep trajectory and it worked just fine.
Is it? These warheads have to reach a significant fraction of orbital velocity. North Korea's test isn't really relevant here, as we have very little details on the actual test. There's a reason the intermediate range nuclear forces treaty existed. If it was possible for any missile to target europe, then it wouldn't have been necessary in the first place (and would have been nonsensical). When you're travelling that low, at that speed, the only option is really going to be hypersonic glide vehicles.
Now the hypersonic missiles are a recent development, and it's not clear how many have been deployed or even constructed. I'm in agreement that they could easily target europe though.
The question with Iskander is how many are currently deployed with nuclear warheads, and how long would it take to increase that number? They seem only useful in a first strike, but any attempt to load them with nuclear warheads would likely be seen by NATO intelligence.
Gravity bombs, if they're used in a first strike, it won't be a decapitation or even a strategic strike; it'll just be a demonstration of force.
Also, when the US anti-missile shield facility were installed in Poland and Romania Putin explicitly warned that these two countries will be added to the predetermined target list:
https://www.reuters.com/article/us-russia-europe-shield-idUS...
And a second strike is kind of by definition counter value.
Leaked Soviet era nuclear war with NATO plan:
> Vienna was to be hit by two 500-kiloton bombs, while Vicenza, Verona, Padua, and several bases in Italy were to be hit by single 500-kiloton bombs
> Stuttgart, Munich, and Nuremberg in West Germany were to be destroyed by nuclear weapons and then captured by the Czechoslovaks and Hungarians.
> In Denmark, the first nuclear targets were Roskilde and Esbjerg. Roskilde, while having no military significance, is the second-largest city on Zealand and located close to the Danish capital Copenhagen (the distance from central Copenhagen to Roskilde is only 35 km or 22 mi). It would also be targeted for its cultural and historical significance to break the morale of the Danish population and army.
It's not me saying that NATO should not attack at all. Having even 300 nuclear warheads shot at you is no good news at all, and you need to preempt that at any cost, including doing a first strike/sabotage on your own.
The number one reason why USSR/Russia never attacked Europe is because it can't attack Europe, and US at the same time. And this is the easiest explanation why Putin been driving a wedge in between EU, and USA for all his 23 years in power.