War Switch Code

[tox_von]

I want to make a mod where instead of when your at war with a civ it joins a rival civ and your at war with both. I want to make a 50 % chance it capitulates and 50% chance it joins in a defence pact with the other civ but your war status with them is whatever the main civ is eg mostly not war. How would i do this? Where is the code for this? Is there any mods that already do this? Does anybody agree this is a good idea?
I posted this in the main section before i noticed this forum but havent got any responce.