Here is a scenario I posted in SHWI in 2001, it needs a lot of work, and may be ASB, but it does Balkanise almost everything
1st POD in 1816 - Congress of Vienna
1 South Wins ACW - 1863 after win at Gettysburg
1.5 Texas leaves CSA - 1860's
1.7 Brigham Young Declares Deseret independent after the south wins
2 Anarchists through the 19th Century advocate small countries as a stepping stone to anarchy. The US starts disintegrating as anarchists take positions of power in most of the states, counties, cities and towns. What was the United States in 1860 now consists of The CSA, The Republic of Texas, The Deseret Empire (such as it is), The Western Union (CA, Oregon, WA, Idaho [Navada in DE]), a vast collection of communities in the centre of the north, the rump of the USA (Maryland, Pennsylvania, New Jersey, NYC and Long Island, The New England Federation (New England States), and the 3 former counties of Delaware in 1900.
2.5 with out a USA threat the Confederation of Canada is mostly just Quebec and Ontario with the maritimes, Alberta, Saskatewan, Manitoba join later. British Columbia doesn't
The Great War, starts the same way, CSA helps the Allies win, The Russian Revolution goes as OTL.
3 1919. The flu goes deadly in South America with large death tolls, the countries collapse in on themselves leading to communities to go their own way.
4 1929 - The great Depression starts in The CSA - the Atlanta stock exchange takes a large dive
5 1930 Anarchy (small countries) starts to take hold in the northern CSA, towns, counties start leaving.
6 1931 Western Australia leaves Australia
7 Through the 30's the CSA disintegrates as does part of Texas, Mexican states revolt - successfuly. Alberta, Saskatewan, Manitoba leave Canada 1939 - whats left of the CSA is Alabama, Florida and Georgia, of the states that left only Louisiana is intact. The Western Union Splits up leaving the Deseret Empire as the dominant force in the non British North America
8 World War 2 starts the same way but without the US it lasts longer - to 1947 the Nazis and the Soviets both develop nuclear weapons and then they annihilate each others cities simulataniously, German V3 rockets hit Soviet cities and Russian long range suicide bombers hit German cities - most of Europe goes down the gurgerler, it is shattered, small communites develop.
9 This leaves a Cold War between the British Empire and the Japanese Empire. The British have Africa, the Middle East and India (colonies, Aust NZ Canada, Alberta, Sasketewan, Manitoba, Newfoundland, Ireland and British Columbia are independent). The Japanese have much of China, Indochina, Siam, the Philipeans, the former Dutch East Indes, PNG and most of the Pacific (including Hawaii since the US wasn't there to get it)
This lasts into the 60's whilst the British work out nuclear weapons on their own. The Japanese start developing Biological weapons
10 The 3rd world war starts in 1965 when British ships are fired upon when entering the south China sea, There is a war of attrition for about 4 years, then British subs fire nuclear bombs at Japan, Hiroshima, Nakasaki and Kobe are distroyed. The Japanese retaliate with a highly contagious virus that kills within a week, it is released in Calcutta and spreads through the population of India like wild fire and this Plague spreads around the world (Actually just through the British and Japanese Empires), Before Britain gets hit, some overjelous general nukes Japan into radioactive pulp. there is Chaos in Africa, India, China, Indochina, the east indies and the Pacific until 1972, when the plague halts. China decends into warlordism as most of the Nationalists and Communists died in the plague, and many small countries arise in India, Southeast Asia and Africa. Each island in the Pacific is independent.
Britain is weak
Australia is the main power now, Canada too but it was hit by the plague,
11 1976, Tasmania leaves Australia after Prime minister is sacked by the governor general.
12. 1977 Scotland and Wales declare themselves independent of England as corruption starts to set in in the post war climate, breif conflict ensues but is resolved quickly
13 Deseret Empire has been expanding on some of the surrounding small communities, many sign mutual defense pact against Deseret.
14 1980 counties start leaving England when Anarchists gain support.
15 1981 Aboriginal communties in the Northern Territory declare themselves independent of Australia after they say they are unfairly treated, there is a breif fight,
16 A Western Australian farmer declares his farm independent after wheat quotas become unreasonable, the Hutt River Province brings the total number of Australian continent countries to 15. (11 aboriginal countries in the Top End) - 1982
1985 - Deseret - California War
California attacks Deseret on what it thinks is a preemptive strike, except that it wasn't California was mistaken, the War lasts several months, and ends with a truce and with Deseret controlling what was the northern quarter of California.
California is weakened,
1990 - Australia lands on the Moon.
1992 - Deseret lands on the Moon.
1994 - All that is left of England is London and what is southeast of it
2001
Sept 11 - Muslim Terrorists hit Australia's old Parliament house in Canberra and the Trade Centre Tower in Sydney, they narrowly miss the Opera house, They protest Australian Imperialism in the Middle East (Mainly protecting Israel),
Terrorists are tracked to Afganistan - Osama bin Ladan (who isn't butterflied out as Saudi Arabia was least hit by the changes in the timeline)
There is a hint of growing 3 way Cold War between The Muslim Powers (Saudis, Iran, Afganistan), Australia and New Zealand (Protestant Christian) and Deseret (Mormon), The rest of the world is far away from recovering from the plagues (South America, China, Africa, Southeast Asia, Pacific) , the social upheaval of fragmentation (Most of former USA,
Britain, Canada) and nuclear war (Europe, former Russian Empire/Soviet Union)