This TL has (obviously) a surviving (and thriving) CSA, a better colonial France, and a surviving German empire.
Throughout the nineteenth century the CSA slowly expanded throughout Mexico and the Caribbean, and in 1911 the first North American war developed where Britain and the CSA were fighting against America. This would happen again in 1928 with similar results. Britain the CSA, and Japan are allied against America and emerge triumphant with the Confederacy pushing North, Anglo-Canadians coming south and a combined Anglo-Japanese force invading from California. This time though, the treaty is rather harsh limiting the American military, demanding huge reparations, etc.
With Britain keeping a wary eye on America, things go differently in Europe. Germany takes advantage of Norway breaking from Sweden and basically turns it into a German colony. The World War 1 starts in 1921 and has a neutral Britain, Russia and France do better than OTL (primarily due to Russia being far better equipped), but Germany still gives them a thrashing and they collapse into civil war (where the commies win).
So now we have Britain sitting top dog atop a global empire, and Germany sitting top dog in Europe. The two eventually come to blows (1943-6) and France throws its lot in with Germany and Britain is "beaten". It's mostly just humiliated, and the war sees little shifting of territory. Greenland, Iceland and the Caribbean being the exception. German forces seize Ice land during the war, so Canada seizes Greenland to prevent the Germans from taking it. Copenhagen protest, but neither side are budging after the war, so they agree to "buy" the property from Denmark. In the Caribbean, the CSA (being allied with the UK) seizes a whole lot of property with little fuss, and did very little to actually aid the UK, which makes Britain a little angry.
Throughout the late 40s and early 50s, Britain goes into a slump with India, Egypt, Australia and South Africa all going their own way. But by 1959, the Britain that emereges is a lot more sleek and mean.
So when it is discovered in 1960 that America is reneging on their reparation payments and rearming, Britain unilaterally takes on America as Canada and the Confederacy have decided on sanctions and other political measures adding another snub in the already tense relationship between the UK and CSA. The war will see the first use of nuclear weapons (Boston and New York) and a complete unravelling of the Unites States. A communist revolution strikes the nation, and a semi-fascist couter-coup strikes back. America has lost 3 three wars, lost over half of its territory in fifty years, they're pretty peeved.
The world is shocked by the war, and Germany will later admit that they developed nuclear weapon in 1954 but have kept it a closely guarded secret. Japan publically announces their succesful nuclear program in 1961 with the Soviets in 1963, the Ottomans in 1965 France in 1966 and the Confederacy in 1972.
The second nuclear war will take place bewteen India and Japan. After the breakup of the British Empire, Japan was eager to spread its influence in the region. It did this in Hyderabad, and Burma. After several years of consternation and an ailing Nizam in Hyderabad, India decides to overplay its hand and invade. Japan says it has a defense pact and fights back for the small nation. Seven nuclear wepons will be used (four local, and three cities, all Eastern India). Japan carves a few states in the East in the treaty, and life goes on.
The last great conflict (and harshest) was in 1984. Japan eventually pulled out from China in the 50's a s the cost of occupying it outweighed the potential gain. In October 1984, China fought a war of liberation against the occupyers including Japan (Manchukuo, Mengkukuo and Hainan) Germany, France and Britain. Japan used several local area nuclear weapons against China with some success, but in January 1985, it was decided in a Concert of Nations (taking place in Brussels) that nuclear weapons would be used large scale if China did not cease and desist. China thinks its a bluff, but is dead wrong. Over the next month, over seventy weapons of various sizes would land across China and bring it to its knees.
So, by the modern day, there are really no superpowers, just regional powers armed to the teeth. It hasn't had the holocaust, a vengeful Soviet Union. But it has a lot more nuclear war and still has colonization and imperial practices.
i know almost nothing about all american borders..
