Basically, France and Spain has hated each other for ever... Same goes for China and Mongolia as well as Russia versus Turkey... and of course, each of them had vassals at some point of the game and, to spice things up even more, I started both Conquistador events, but declared peace and retreaded the Conquistador Units to my homeland...well, to England's homeland anyways... I always acted as a mediator, ever since I wiped the English off of the face of the globe, I was a peaceful economical empire. Sort of. After a while, other nations noticed that while they were fighting, I was slowly becoming the master of the world, so they declared peace, global world peace (well except for Japan fighting Khmers)... For a time, all was well... Then came 1956.
As you can see, after a global peace, everyone wanted to get in the next global war, well everyone but me... I'm already getting ready to fly off into space while my neighbors are working on destroying the Earth.
Sides are...
Khmer
China
Inca
Germany
France
America
Russia
...against...
Portugal
India
Greece
Mongolia
Spain
Egypt
Turkey
...plus the Japan/Khmer war.... I can't side Japan with the 2nd group because the only war they've had was against the Khmer, they really didn't side with Khmer's enemies... Actually, Japan was the only nation that I trusted wouldn't get me involved in some War I didn't want to be part of, so they're the only ones I signed Defensive Pacts with... I also avoided Vassals as I had more than enough colonies to supply me with anything I wanted.
I'm sure everyone who's played as much as I did has seen a similar large scale war, but what pushed me to post about it on this thread (which I found refreshing when I fell into it while at work - during my break!!! - the other day) is the following... Somewhy, I feel like it's Cold War Gone Wrong... Alright, the war was declared in 1956, but in 1964, the U.S. decided to nuke La Havana (Spanish), making it the first use of nuclear weapons in my game (after Spain refused to sign the anti-nuclear act, teaches them...), a clear reenactment of the Cuban Missile Crisis, what else could I ask for?
Another proof that Rhye has managed to create an add-on that's beyond realism, with each new game, we get to play an alternate reality that always manages to look bone-chillingly familiar, deja-vu-style! Bravo!
Note: This was played on the "old" version of the mod that came with the latest patch.
Re-Edit: As planned, I won the game with a Space Race victory, although I would've won with the highest score and I'm pretty sure I had the ressources (all my cities are coastal, so with the Dutch Dike, most of them pump units -tanks- every turn while every other city pumps them every other turn) to enslave the world for a Domination victory, but that's not the way I chose. Also, if anyone wonders what the outcome of my world war was... Well, Mongolia bit the dust early on, making Russia and China even stronger powers, then, in the '70s, Spain collapsed, quickly making Aztec (Havana, Caracas), Inca (Rio de Janeiro, Buenos Aires), America (Indianapolis, Tampa, Coruna) and France (Madrid, Mellila) the following ruling powers (after Russia and China... and me)... Somewhy, Rome decided to pop back into the game too, taking Marseilles, Rome and Venise from the French. Persia had also just reborn before the War, and Arabia also came back, greatly weakening the Ottoman Empire... About 20 nukes have been lauched, following the initial American bombing of Cuba, so I got paranoid and built ~20 ICMBs, then I just bullied everyone into giving me all they had that I wanted, before launching my spacecraft in 1989, in order for it to land in 1999, effectively avoiding the dreaded Y2K bug...

In the end, Global Peace was back everywhere... well, except for Egypt... Somewhy, everyone that was at war by the time I won was at war with Egypt and no one else... I don't know what they've done, save for appearing right in the middle of the Turkish empire, and right next to re-emerging Arabia. Come to think of it, Turks were plagued by old Civs re-appearing and stealing their cities... Greece, Egypt, Persia, India kept going into civil war and reforming... Meanwhile, Russia wouldn't let Istanbul/Constantinople alone, otherwise, Turks would've ruled my world.