Im pretty much stuck in this situation. Any ideas?

http://steamcommunity.com/sharedfiles/filedetails/?id=138932271 France got me stuck in here. I can defend, but France can just completely expand while I do shit. Im friendly with EVERYONE else. Rome cant beat them, while Germany is on another continent. China is currently at war.

Help?

Edit: Decided to ally the city states, and France took them all out. He has blockaded me in, and Im trying to get Neopolis. Hopefully other Civs will go to war with him now.

Edit2: I lost. I held as much as I could, he took all the city states in the area, and killed Rome. I held out, even when he eventually got ahead in tech. I got nukes, and nuked Paris and Orleans. I did this about 5 times. Still not enough. Ty for the help :P