RTS how to make working diplomation window?

Hello!
Im making RTS and i stumbled upon a problem. Every country has its own folder in workspace. I dont have idea how i would go about making diplomation window, im not sure how to make individual relations between “nations” like war, trade etc. How to make it? Any suggestion or idea?
I would check if war == true then but how i would check with whom player is at war with?
Thanks for reading, i hope theres something to help me out.

Have played sid meiers a bit before.

But this should help since one country can trade with multiple others or be at war with multiple others.