This is the basic world alliance system in 2003.
The 2 great power blocs are the Commonwealth of Free Nations and the Eurasian Alliance and its allies (usually just called "The Commonwealth" and "The Alliance")
The Commonwealth of Free Nations grew out of the old British Commonwealth, which is still a strong and vital institution in this timeline. The Commonwealth of Free Nations was a way for nations friendly to the British commonwealth to join in a larger, looser, less demanding alliance. All nations belonging to the British Commonwealth also belong to the Commonwealth of Free Nations.
The Commonwealth nations all have trade agreements and military alliances. In practice, the larger members, particularly Brazil and the Ottoman Empire, sometimes go off in their own direction with foreign policy and military intervention and considerable strain is put on the alliance (comparable to the US vs. other NATO nations over the last 3 years or so).
One thing that all members of the Commonwealth have in common are fairly democratic, elected governments. There is a mixture of constitutional monarchies and republics, parliamentary and presidential systems of government. Domestically, many of the nations in the Commonwealth follow almost libertarian ideals with low government intervention in the economy. In the English speaking countries especially, classical "laissez-faire" economics was never eclipsed by socialism or even Keynesian-type economics as the dominant strand of thought to nearly the same degree as OTL. In this timeline, socialist-type policies tended to be associated with the centralized and nationalistic governments of the Commonwealth's opponents, further decreasing their popularity. Nevertheless, some members of the Commonwealth, such as Mexico, the Ottoman Empire, Siam, and even Brazil to a certain extent, have traditions of stronger state intervention in the economy.
The Eurasian alliance is based on the 2 core nations of Russia and China. Russia has been Britain's one consistent foe for the past 150 years. Unlike in OTL, Russian Tsars as early as the 1830s in this world began pushing for strong economic development. Russia's industrial growth in the 19th century was much faster than in OTL. In the late 19th century, the government began to adopt some socialist-style policies to get both peasants and factory workers on its side. The official ideology was constructed around an extremely nationalistic form of what in OTL was called "slavophilism" - the idea that the Slavic peoples are a unique group that deserve world leadership, and that Russia is the natural leader of the Slavic peoples. Under this ideology, the Russian government developed a quasi-fascist type of government in the early 20th century - nationalistic, strong military, emphasis on "national destiny", corporatist economics with government having a major hand in both capital and labor, a "rubber-stamp" legislature, lots of propaganda, etc. Earlier in the 20th century, Russia's main allies were a nationalist, monarchical France and a Shogun-ruled Japan slightly subservient to the Russians. Those two nations were defeated in the Great War of 1937 - 1943, but the Commonwealth and its allies were too exhausted and war-weary to continue the fight against Russia, especially because Russia developed and tested its first atomic bombs at almost the exact same time that the Commonwealth did.
Even as the Great War raged, Chinese nationalist forces with Russian support inflicted a series of defeats on the weak pro-Commonwealth government of southern China, and were able to seize control of the entire country.
What followed were decades of alternating high military tension and "detente"-like lower tensions where economic competition became more important than military.
Russia and China both have internal dynamics somewhat similar to OTL China over the last 20 years - repressive governments combined with strong, capitalistic economies (though the government is also neck-deep in business ventures). Many in the Commonwealth hoped that liberal economics would lead to rising demands for more democratic governments, but this has not happened to nearly the degree they had hoped.
Many of the other nations allied to Russia and China have similar political/economic systems. To a greater extent than the Commonwealth, though, the Alliance is driven by negative factors - fierce competition against the Commonwealth.
The Paris or unaligned pact started in continental Europe and later branched out to recruit member nations in other parts of the world. It's kind of like a combination of a more loose-knit EU and a more effective "non-aligned movement" from OTL Cold War.
