Why do people specifically state 'nation state' in these circumstances? What do you think makes a nation state a particularly notable adversary relative to countries which aren't nation states like the UK or the US, which seem to have more capability in this area not less?
Do you have any creative alternatives that don’t step on the traditional use?
When they say nation state, the mean a government.
That's not what 'nation state' means at all - a nation state is an international state that is also a nation. So pretty much orthogonal as to whether they're a competent cyber force or not.
But this isn’t unique to nation states.
I favor APTs as a term, since it denotes any actor with lots of technical means and a political/strategic rather than financial agenda. Many APTs belong to nation states, but that's not always true!
I'm sure a lot of people from the UK would pedantically insist on the multiple nations point, based on my past experience on the internet. On the other hand, in the US, people declare it to be "one nation..." and so saying it is not a nation suggests that the determination is made more from an outside vantage point than a traditional American one.
The Wikipedia page on Taiwan has some information on how people there view themselves. It seems that basically, people may be largely divided between those who came from mainland China after WWII, those who came in earlier waves of immigration, like the 19th century, and "aborigines" who came much longer ago (but it seems there were people from China on the island even before them) These may not seem like large differences, but it seems like they are tied up with the overarching question of the status of the ROC as being separate from China or not, of whether people are Chinese, Taiwanese, or both. And the question remains, do people determine for themselves if they are a nation, or do outsiders do it "objectively"?
A definition can be stated without it being practical to use.
They are, as the term is usually used; the United Kingdom and U.S. are nations. In the former case, it is sometimes argued that the constituent countries of the UK are nations rather than the UK itself; they certainly are historically nations and may be so presently, but nationhood isn't exclusive; the UK definitely has a national identity whether or not England, Scotland, Wales, and/or Northern Ireland also do.
The US is a more clear case of a Nation with a strong national identity and without anything even arguably competing the way the constituent countries of the UK do; yes, it's people have many ancestral nationalities (which is true in many nation-states), but that's hardly relevant to whether it's a nation-state. Since the advent of the idea of nation-states as a general norm, many polities have built national identities to form nations that coincided with the State and displaced ancestral nationalities as the locus of attachment for subjects of the state, often as deliberate projects.
However, what I was responding to seemed to imply that they weren't under some self-consistent definition that everyone really should use.