Unfortunately in the free market, the most skilled will aspire for the perfect balance of high pay and relaxed/flexible workplace. Neither of these would seem to be a good match for military/intelligence service jobs, with their "yessirs" and suits, so it seems to me the governments have a crisis on their hands.

The OP talks about volunteer services, which has crossed my mind also, because it would probably work in a national emergency situation, but by then it's almost certainly too late. The people with the required skills are going to be the slowest to get all patriotic. Not that they wouldn't, or couldn't, it's just that they're not likely to be the nationalistic type so it would take longer before they were convinced of the threat. And then by the time they'd been screened it may be too late.

The best analogue to this is Bletchley Park in Britain in WWII. And in that situation the country was already at war, so the best minds for the job could be pretty much told what to do (or else be sent to the front line). And even then, the people were by all accounts pretty difficult to manage.