TropicoleaksG 10

Build a Spy Academy, hire some teachers, and get agents trained. Once you have some, go to the Espionage menu and assign agents to Expose Secrets. You can assign half your agents to one superpower and the other half on another superpower.

Now I did this achievement during the World Wars era so the Allies and the Axis are the only Superpowers, but once the EU, China, and the Middle East join the game, they are also considered Superpowers and count towards the achievement as well.

If your agents keep failing to expose secrets, you can purchase the License to Kill upgrade to improve your odds. However, if your agents fail, they will be killed and you'll have to wait until more can be trained. I didn't buy the upgrade and didn't have too much trouble.