So I have pitched this idea before but right now I have fleshed it out a bit more. The idea first started when I was about eleven and was thinking about a story for class about a fifties London where crime ran rapant, drugs were everywhere and a massively cataclysmic war had just ended (Think WW1+Thirty Years War). And as I was thinking about this I became more interested in the war itself. So I drew a map of the war, The war was pretty much East v. West with a United Scandinavia, Britain, France, Germany and Italy on one side and Russia, Austria the Ottomans and some sort of Baltic Nation on the other side. Later when I joined this site I realized the map was pretty unrealistic so now I have decided to flesh it out more.
Napoleon wins at Waterloo, the massive British defeat causes a collapse in the British economy and Britain makes a seperate peace with France. Prussian forces retreat back to the Rhineland. Napoleon realizes that his victory could be short lived and moves for a lightning strike at Austro-Russian forces mobilizing near Bavaria. This battle is Napoleon's final defeat, Napoleon is killed during the battle and the emporers forces begin to crumble. A final surrender is obtained from Marshal Ney the following day. The day of July 29th 1815 is the end of almost 25 years of continual conflict.
In the mid 1800s Russia invades the Ottoman empire and Britain and France immediately move to contain them, later due to a diplomatic incident Prussia joins the fight on Britain's side and Austria joins the Russians. It ends up as a stalemate in Europe but the Russians achieve a favorable peace on the Ottoman Front. Later in the 19th Century Austria and Prussia go to war, Prussia achieving such a smashing victory that they are able to force the German states into a nation under the leadership of Prussia, although some of the South-German states remain independent with close ties to Austria.
In the early 1900s tensions come to a breaking point and the before mentioned cataclysm occurs, with the only differance being the Ottomans are now on the side of the Allies.
Sound good? Needs some fleshing out but I think that with some work I could get it to work.