Hong Kong represents more than a powerful economic hub for the People's Republic of China. It's recent protests are more than just a demand for return to the 'One Country, Two Systems' policy. The matter of Hong Kong is of paramount importance to Chinese leaders because of optics. If Beijing allows Hong Kong to resume its sovereignty and right to self governance, they risk allowing the same sentiments to begin growing in other regions unhappy with China's leadership and aims.

Despite the immense Han majority in Eastern, Costal China - the Republic's greater territory is a patchwork of unassociated ethnic groups and socio-cultural beliefs that share little in common with Beijing's collectivist approach. This is not unique to China - American territories, European colonies, the British Raj, the Japanese Empire's conquered land, and Soviet satellites possessed many of the same qualities and dissonances. Subjugated locals were (and rightfully so) unhappy with far-away capitals determining their rights and governance. If Beijing allows Hong Kong to gain greater autonomy, they risk giving the green light for Taiwan, Tibet, Macau, Xinjiang, and even some of the central provinces to do the same. Beijing consistently places emphasis on stability and interconnectedness above all other qualities in their rhetoric. The stamp on dissent when it appears, for if it festers, it make provoke a backlash they can't control.

This has happened to Beijing several times in China's recent history. Unlike the United States, Beijing has historically asserted its continent-wide dominance over highly populated communities with long, rich histories. The United States may be the only continent-sized nation that did not have to compensate for its size by accommodating the various mini-nations that lived under its banner. Inner Mongolia, Xinjiang, Tibet, Hong Kong, Macau, Taiwan, Manchuria, and the Coastal Cities all have historically differing interests than a support for a common China. The government in Beijing has fractured at several points throughout history, often when one of the fringe states is empowered by a weak capital, supported by a foreign nation that they share greater ties with, and the Costal Regions are apathetic. Therefore it is no surprise that modern China prioritizes national unity over all other qualities (and might provide one insight why the one-party, authoritarian model is so appealing to Chinese power brokers).

The stakes are about the same for Greater China as they were for the Soviet Union. Like China, the Soviet Union desperately needed the fringe regions for their own geopolitical security. Xinjiang and Tibet are essential parts of China not because they're economic boons (though they do both possess some important mineral resources), but because they allow China a buffer between themselves and potentially hostile rivals like India or the Russians. Despite cultural dissimilarities between the ethnic groups that populate the two fringe regions and the Han Chinese that control power in Greater China's political and economic centers, they are on the inner side of natural boundaries that grant the Chinese an ideal strategic position. The Himalayas and the Karakorum Range running through Tibet and Xinjiang are high ground, versus the relatively flat lands that connect the pair of provinces with central China. If the Russians, Turks, or Arabs were to gain a foothold in Xinjiang, they could easily have a garrison to use as leverage against China. Likewise, if Tibet became a client state of the Indians (likely, as Tibet's relatively unpopulated and has little economic potential), they could just as easily use it to garrison their own troops to use as leverage. Would either group really be a threat to China's 1-million strong PLA? No. Would it be enough of a nuisance to factor into strategic planning? Without a doubt.

Like the Domino Theory that caught fire among Western strategists during the Cold War, Beijing views the revolutionary protests of one fringe as a potential spark which could become a wildfire that enflames the rest of the country. Backing off of Hong Kong (or Taiwan for that matter) would signal to activists and protestors in the fringe regions that if they put up a significant fight they could have leverage against Beijing. The Chinese government cannot tolerate this.