There is a fundamental gap between how Americans perceive China and how China's leaders perceive China. That gap is as wide as the Pacific Ocean and it is crucial for understanding what's happening in Hong Kong today and how China's leaders will respond to it.
Americans see China for its strengths: its massive size, powerhouse economy, exploding growth, miraculously expanding cities, booming industries, and growing influence on the world. Even the fact that many Americans see China as a threat is ultimately a compliment to the country, treating is as a near- or soon-to-be-equal.
Chinese leaders (and most Chinese people, for that matter) have a view of their country that could not be more different. They see their country and government as so weak, so embattled by existential threats from without and within, that the possibility of chaos and collapse is seen as immediate and omnipresent. Here is US-based China expert Patrick Chovanec:
The rest of the world may see China as strong, but its leaders see it as weak, threatened, and potentially unstable.— Patrick Chovanec (@prchovanec) September 30, 2014
China's rulers fear that any concession, any failure, any loss of control could send the country spinning into chaos.— Patrick Chovanec (@prchovanec) September 30, 2014
This is essential for understanding what's happening in Hong Kong, where thousands are protesting the Chinese government for partially reneging on its promise to grant the semi-autonomous city full democracy in 2017. For the Chinese leadership in Beijing (which has ultimate authority in Hong Kong), these protests are not just about whether or not Hong Kong gets full democracy. They're not just a matter of saving or losing face. They are almost certainly seen as a potentially existential threat to the entire Chinese system, which is perceived as so weak and embattled that leaders believe even peaceful protests like this could bring everything crashing down. And they are certain that, were the system to collapse, it would take all of Chinese society down with it.
There is some history to support this perception. Especially in the last few centuries, a number of Chinese governments have collapsed, and China has gone through several national traumas of such severity and scale that they are difficult to even imagine. The 1851 Taiping Rebellion killed tens of millions; so did the famines of the 1958 Great Leap Forward. The 1862 Dungan War and the 1876 famine each killed as many as 10 million Chinese. There have been a number of other famines, wars, and floods. A history-minded Chinese leader might not see that as ancient past, but a continuous series of events.
And when Chinese leaders look at their country's position within the world, they tend to underestimate their strength, seeing China as a weak country surrounded by hostile foreign powers. The "century of humiliation," in which Western imperial powers bulled China and carved out colonial concessions (including Hong Kong to the British), ended some time ago, but is not viewed as so terribly distant or different from today.
It doesn't help that top Chinese leaders are engaged in a series of never-ending struggles against internal political rivals and enemies — struggles that can end in disgrace, prison, or even death — reinforcing this sense of insecurity and paranoia right into their private lives.
This worldview is why Chinese leaders are so concerned about the protests in Hong Kong. They show every indication of being absolutely terrified that pro-democracy protests could spread into mainland China. That's something that Chinese leaders have long considered such an existential threat to their rule and to China itself that they have consistently gone to remarkable lengths to stop it, including, don't forget, having the military massacre 2,600 peaceful protesters in 1989 who were asking for a lot less democracy than Hong Kongers are today.
That doesn't mean we're headed for another Tiananmen, but the point is that to understand how China is reacting to the events in Hong Kong you have to understand how Chinese leaders see their country and its place in the world.