[relax88]

If someone were to gain some kind of advantage that could prevent a retaliatory nuclear strike, then I could see it. Otherwise I highly doubt it. World War 2 offensives were made possible by the advances in mechanized and aerial warfare.

Interestingly enough the US has been retrofitting their nuclear arsenal with better targeting systems, making it much more effective. The Russians don't like this, which is why you hear talk of hypersonic missiles, autonomous submersibles carrying nuclear warheads, etc.

Perhaps some kind of neutron-based weapon could be developed to counteract large numbers of incoming ICBMs in the upper atmosphere, or to destroy an enemy nuclear arsenal in place. There we concepts like this, and the US even built some for defense against ICBMs (The W66 warhead).