>I don't think reliable defenses against nukes can exist can they? Airbursting nukes high enough causes emp events and the irradiated material still floats around
With enough anti-missile technology, it's possible (though challenging) to defend against that.
But good luck trying to stop them from smuggling a multi-kiloton device across your border and detonating it at a time calculated to cause the most casualties.
I'd say that's debatable, but whether its possible isn't really the point: it's important to have both eyes open on the actual ramifications of nuclear weapons not being a reality anymore. Because the idea that that is "the peaceful option" isn't one borne out by history - past or present.
With enough anti-missile technology, it's possible (though challenging) to defend against that.
But good luck trying to stop them from smuggling a multi-kiloton device across your border and detonating it at a time calculated to cause the most casualties.