They had a similar system in Birth of the Federation-it was fantastic!!! You invested resources (population and money) into generating
so-called 'Intelligence Points'-which you then allocated to different nations. In BotF, though, you could further break down your investment into Espionage or Sabotage-and even in specific AREAS (like Economic, Military, Domestic, Scientific). The underlying premise was the same, though-the more you invested, the more frequent the attempts AND the greater the chance of success. You could also invest points into Internal Security-to PREVENT enemy intelligence operations. What really made it work, though, was that it is a % based allocation system. So, if your intelligence points rose from 100 to 200, your allocated points would rise accordingly-reducing the need to Micromanage your investment.
Yours,
Aussie_Lurker.