This is all old fashioned muddled thinking again. We face no threat from any nation state armed with nukes, we do however face a significant threat of a nuke, chem or biological weapon being detonated in one of our major cities or at a major public attended event.
This threat comes from al Qaeda and it's almost franchised supporters. Who are you going to launch a nuke at then?
Ballistic missile or cruise missile, they all seem pretty pointless in todays world.