The United Federation of China was the culmination of a decade's of work by the Unity Society of Taiwan and the Social Democratic Alliance in the waning People's Republic, with a little help from American economic and military support to combat the Japanese during the last World War. Formally founded in 2058 the new China looked to have finally gotten over the millenia of cycles of growth, disparity, and revolution that had plagued Chinese civilization since its inception. The Federation shared in the prosperity of the post-war world, its economy bolstered by American investment and the return of its low lying coast-lands after the refreeze that let the Chinese rebuild their greatest cities. The flood had driven millions of Chinese inland, and driven a new kind of cultural revolution that spread the wealth and skills of the richer coastal areas to the poorer inland provinces. When the waters receded, and Shanghai was returned from the seas, the children of those pilgrims to the frontier returned to their parent's cities, and built an economic boom that returned China to its position as the economic heart of Asia, and the second largest economy on Earth.
The prosperity was short lived, as it was for every nation by the end of the 21st Century. The population crisis of the Americans could not compare to that of China. Where the United States began to feel the stings of an inflated workforce made redundant by advances in robotics and automation by the late 2070s, China had been reeling from economic depression for most of the decade. When the gates opened for a new wave of colonists to Mars in 2081, was it any wonder that the Chinese saw the largest transfer of citizens to the American space colonies? Over half a billion people from China flooded to the colonies in the space of 20 years, abandoning their homeland for the promise of a better life in space. For those that stayed behind, a power vacuum was left by the elites that had fled. By 2096, many Chinese leaders sought to adopt the Quantum Economic Model that had freed the colonies from economic disaster. After several pilot programs in Shanghai, Hangzhou, and Nanning, the government began to move forward with plans to be the first nation on Earth to implement the colonial model. Unfortunately for the Chinese, the Mex-American Cold War intervened.
China was America's strongest ally in Asia, and its military was often involved in proxy wars in South-east Asia and the Pacific to counter Mexican sponsored separatists. After the end of the Second Vietnam War, many Chinese soldiers returned home to not only find their economy still devoid of opportunities, but the Federalist government delaying pensions for veterans. The whole situation was a powder keg, and Mexico was quick to exploit it for their own benefit. After making contacts with local regionalists, Mexican operatives quickly established separatists movements from within local Chinese Army regiments. With a little social engineering, all of Southern China was quickly in open revolt against the Federalist government in Beijing. The revolts in the South eventually became a coup de tat that forced the Americans to invade and pacify the Chinese capital. After a short, but costly civil war, some order began to be restored by 2108 and a provisional republic governed from American-run Shanghai had been propped up. Taiwan and Manchuria were in open rebellion, but not by Mexican sponsored revolutionaries, but revolts from local governments who refused to submit to a government so incapable of keeping the country in one piece. As the Americans and Mexicans grapple for dominance, it is not yet clear how much of China will pay the price.