Carrie Lam, the city’s chief executive, has said the law will ensure “the long-term prosperity and stability of Hong Kong.”

States and separatists

Anti-separatism is the norm worldwide, no matter the desires of many peoples around the world for a country of their own, or the oft-stated importance of “self-determination” as a principle of international law.

“Since the end of the Cold War, a global norm has prevailed enforcing cartographical stasis, a freezing in place of the map as it existed at the end of the 20th century,” Keating said. “This norm prevails even as ethnic and religious conflicts rage within the countries on the map.”

Contiguous China

There is likely nowhere that this norm is stronger, or more strongly avowed, than in China.

The same is true for other parts of China often called inseparable by the government, including Tibet and Xinjiang. While these territories were also often under Chinese control or influence, it was as part of a wider imperial system wholly removed from modern conceptions of nationhood.

“Modern China’s borders do not correspond to the historic boundaries of shared culture of the ethnic Chinese (or Han) people, nor to the boundaries of the premodern Chinese state,” Esherick writes in “How the Qing became China.”

“Fully half of the territory of present-day China was acquired by conquest during the Qing dynasty, a dynasty in which the ruling house was not Han Chinese but Manchu intruders from beyond the Great Wall. Most of this expansion took place only in the 18th century.”

Sam Crane, chair of Asian studies at Williams College, said many states and territories which paid tribute to the Qing Empire and were under its sphere of influence would not have been regarded as part of China or Chinese civilization by Beijing.

“Imperial political control did not assume a singular, common, modern national identity,” he said. “Once we get to 1949 the assertion that Tibetan and Uyghurs are part of the ‘Chinese nation’ is established to a much greater degree than under the Qing, and the attendant political stakes for demanding greater autonomy are, thus, much higher.”

Anti-separatism

The modern idea of a nation state — of a people united by common culture, language or ethnicity — is traditionally pinned to a series of treaties in the mid-17th century, when the Holy Roman Empire recognized the independence of two non-monarchical states, Switzerland and the Netherlands

That marked, according to Keating, the point after which nation states increasingly became “the most significant units in international politics,” becoming more important than rulers or empires amid a rise in nationalism continent-wide.

This did not take hold immediately and the break up of the great empires of Europe would not fully occur until the 20th century. In Asia, too, it was not until the Qing was challenged by the new assertive nation-states, particularly Britain, France, and Japan, that the conception of the empire began to shift in a similar direction.

Despite its adoption of imperial borders, since the fall of the Qing, China has reinvented itself fully as a modern nation state, advancing an encompassing idea of Chineseness — a language and education system that encourages all within its borders to identify with being part of China.

The nation state concept has also been expanded backwards through time, so that former imperial territories like Tibet and Xinjiang, whose traditional peoples had little connection ethnically, linguistically or culturally to those in China’s east, become “part of the country since ancient times,” as Liu and other Chinese officials have argued.

Writing about the global norm in favor of the status quo, Keating said “the assumption has been that if secession movements were allowed to succeed, it would open a Pandora’s box of dangerous separatism.”

This is perhaps especially true in China, where a single pro-independence domino could set off a cascade of territorial unrest.

Beijing has dealt with desire for independence in Xinjiang and Tibet, in part, by encouraging the mass migration of Han Chinese to both territories, as well as advancing Sinification policies in education, language and religion. The changing ethnic makeup of both areas makes it harder to argue for self-determination based on an idea of racial or cultural difference to China proper, with millions of Han Chinese living in both regions.

Hong Kong and Taiwan threaten the status quo in a different way. Both are majority Han Chinese, and antipathy towards Beijing in these areas is based not so much on nationalism but as a rejection of the mainland’s political system. Were either territory to become fully independent, this could undermine the PRC’s claims of legitimacy, based as it is on the idea that a historical China has always existed and always should.

Challenging this idea is controversial anywhere — as much in China as in the UK over Scotland, Spain over Catalonia, or Russia and Ukraine over Crimea. But as Keating writes: “The existing countries in the world aren’t good in and of themselves; they are useful to the extent that they help provide security and general welfare for the people who live within them as well as for the world as a whole.

“When they fail to do so, our first impulse should be to ask how they can be improved, not simply to state that they must be preserved.”