CN has been shrinking, not rapidly, but enough to say it`s shrinking. To me there are a few reasons.
1.Game Mechanics get Very Repetitive and eventually pointless
2. No new features recently that changes something largely.
3. No UN which just about everyone wants
But one i don`t think most people relize another important part. No large wars. When the game was growing and thriving, People and there alliances where agreesively fighting other alliances. But now a alliances are taking a real world approach and attempting to stop wars through Diplomatic ties.
But it has made the game take a huge hit. People just aren`t as interested when alliances are so wrapped up in alliance politics, they can`t get approval to attack this guy who just nuked him a bunch of times.
Ao to me a way to save the game is to let alliances duke it out, let the gloves come off. Peoplelike strategy games, not repetitiveness.