[I couldn’t agree more on what you said. If you choose the hard settings for your campaign, diplomacy will be impossible.. You will end up attacked by everyone and will have to fight countless battles each and every turn of the game. If you go for medium on the other hand, you will find diplomacy more realistic and will be able to "create your own difficulties" according to your own will, playing a more flexible game. You will be able to back up your allies properly until the end of the game; will be able to experiment different strategies and will not need to stab allies on the back in order to win the game. Despite CA´s improvements towards diplomatic, political and economical issues, there is still need for more. You should be able, for instance, to support your enemy’s enemy on war, or to destroy your enemies’ farms, blockade their ports and destroy their economy, therefore forcing them to sign a deal etc... Diplomacy and strategy is better than it was before but not good enough yet.

If you want to have fun while playing - and not simply beating at any cost the computer in order to win the game doesn’t matter what - I would recommend exactly as Lord Curlyton said: M/M or M/H.