Totally Don't Spies

Spies hurt your enemy but hurt you more in the long run. That's how being dishonourable works. It's fine to have agents. 100% have folk living normal-ish lives in the other country and telling you about it. Sigint; sure, if you can intercept their messages, go ahead. Don't have someone lie about their loyalties. If they betray others they will betray you, but more so. 

If you don't know what your enemy is going to do, then prepare for both possibilities. Get trained in imaging all the possibilities, so you stop having blind spots and can't get blindsided. If preparing for both possibilities means you can't properly prepare for either, you already lost. Surrender the position. You never owned it in the first place. Retreat to a defensible position. 

Having spies will fuck you right up. Journalists are bad, but all the editors are literal CIA agents now, which, somehow, manages to be even worse. 

At most have anti-spy camp. Have a fake city where spies go to play, so you can learn counter-spycraft. Hire your own spies to spy for real on your fake city for the express purpose of learning how to catch them. Since they're in reality your spies you wouldn't prosecute, and instead re-start the game when they're all caught. End up with super-sophisticated spy tech (which you largely don't use) and super-sophisticated anti-spy tech. If you don't catch them they can tell you what you missed and have another go. Maybe perform corporate espionage on real countries but keep the secrets confidential and tell them how to fuck up less, instead of selling the secrets.

Maybe have a spymaster if they consistently rat out any traitors who try to sell information. A real sociological institute would have to employ a spymaster. Trying to work purely on open information is just stupid.