I don't have such a feeling at all. It is my understanding(and please correct me if I'm wrong) that even with the best technology there is little to no defense to ICMBs. We have tech to stop some missiles, but with the sheer number of them in existence and the fact that every ICMB carries 12-16 warheads which split off early in descent stage, I think you can quite safely say that whatever target needs destroying it would be destroyed. Then there are weapons like the Russian System-6 torpedo which launches from a sub and detonates off shore to cause a gigantic tsunami destroying any coastal city(and if that wasn't bad enough, it can be salted with cobalt so that any area flooded by the tsunami is uninhabitable for at least few hundred years).

I don't know what sort of confidence level you'd need to have in your defence systems to even start thinking of actually using nuclear weapons against another superpower - the risk is just too great.