Not commenting on GP post, but it is an area where I would not trust domain experts. This kind of work is typically very classified and experts have clearances. Having a clearance mean you can't talk freely, the more you know, the less you can say. Ideally you say nothing at all about your work, but I know some of them will simply repeat what is found in newspapers when asked. The less accurate, the better.

People without clearances, working on a domain that is tangential but not the domain itself are probably more reliable, as they don't know truths that cannot be told, but they know enough to make informed guesses.

I take this article as informative but only for the general idea. The part about which country has what capabilities, I give absolutely no credence.