Any nation state can build pretty much anything (albeit over a varying time period), because at the State Level the budgets can be billions, no commercial pressure and also immunity from prosecution (e.g. a Chinese spy caught would be traded for something or another and returned home and state authorised hackers based in China won't get extradited).

The only thing to stop them is the will of more powerful states.

If you take Iran as an example, they would have possessed Nuclear weapons long ago if it wasn't for USA/Israel as Iran as a state will throw everything at it.

p.s. And that's a very detailed and well laid out visual article above usual broadsheet standards.

Kind of.. but at the same time:

A nation state will fail at most things, because there's no budget, and there's commercial pressure, democratic pressure etc.

One of the few things to make it work is lack of competition. Iran: they have a nuclear program because they can't buy what they want from the market.