Is there a way to know which country is at war with another country? I know that there is the Diplomacy Panel, but it only tells my situation with other AI civilizations. What I want to know is : Is there a war between other civilizations (AI)?
You can get a lot of information about other civilizations through the
Diplomacy Overview screen. You can access this screen through the drop down menu in the top right corner. This menu is accessible by using the button next to the
Social Policies button. Once you open up the Diplomacy Overview, click the tab labelled
Global Politics. A screen like this should appear, which informs you of the relationships of each opponent:
The InfoAddict mod is very helpful. One of its screens shows a circle of civilizations with lines connecting them, each colored to denote different conditions: war, open borders, trade agreements, attitude, etc. This is similar to the Diplomacy Advisor from Civ4 but with much more information.
It doesn't break saved game compatibility so you can safely load it for use with an existing game.