You don`t understand. Take the map. Look Britain, France and Germany. Only few nukes explode and they are nothing. What would their submarines? Some would sacrifice themselves and most would simple escape to USA. What would USA? USA would ask for peace.
Poland is especially vulnerable
Poland is safe. If Poland gets nuke it would always be on the scenario of EU and NATO. By their doing. No matter who use the nuke. So Slavic world would retaliate. Why? Destroyed Poland would create such a dis-balance within Slavic world and Russia would be forced to act against EU and NATO powers in order to avoid total moral defeat within Slavic world. Simple, nothing would be same without Poland. It would turn to fanatical war for extermination of old enemy that is behind Drang Nach Osten and all evil came from it. Russia would be forced to use maximal force and after China join (because China must join for geo-strategic reasons), USA would be destroyed.
See? USA knows this and USA wants to avoid this. That is why Poland wont be harmed.
Just one nuke fall on Poland and thing turn into war to the extermination.
Why do you thing elite of Poland allows heavy arming of Serbia from Russia via Poland`s air space.
Stronger Serbia, bigger chaos in Europe if Poland is harmed.