Last week, China’s National People’s Congress set in motion new, restrictive legislation for Hong Kong. Activists in Hong Kong have already dubbed this move as the final nail in the coffin of the Basic Law, which guaranteed the people of Hong Kong a high degree of autonomy to govern their own affairs.

Beijing has previously made promises of autonomy in other restive regions — like Tibet. Grasping how Chinese leaders have repeatedly offered Tibetan autonomy, only to rescind it, reveals what the future might hold for Hong Kong.

China annexed Tibet in 1951

Following a brief military campaign in Tibet, in 1951 Mao Zedong promised the rooftop of the world the right to self-governance — if Tibet in return accepted it would become a part of the newly founded People’s Republic of China. The 17 Point Agreement, signed by representatives from Beijing and Lhasa, codified the terms of this deal.

Tibetans soon discovered this “autonomy” was highly limited — it encompassed only those issues that did not infringe upon the broader vision Beijing had for China. And autonomy was, at best, unevenly applied across ethnically Tibetan regions (with the earliest encroachments against Tibetan autonomy occurring in Kham and Amdo).

By 1959, armed resistance to Chinese rule in Tibet had intensified to the point of open revolt. The rebellion proved to be short lived in the face of vastly superior Chinese manpower and weaponry, however. During this tumult Tibet’s spiritual leader, the Dalai Lama, fled to India. He has remained in exile ever since.

Formally, Tibet is an “autonomous region”

After crushing the rebellion, China again offered Tibet the promise of autonomy with a new political framework for Tibetan self-governance: the formal establishment of the Tibetan Autonomous Region (TAR) in 1965.

In theory the TAR, like China’s other autonomous regions — Xinjiang, Inner Mongolia, Ningxia and Guangxi — cemented Tibet’s status as an autonomous entity. But the Cultural Revolution (1966-1976) ripped through all of China shortly after the TAR’s establishment. The impact was particularly harsh in Tibetan regions as Mao’s Red Guards destroyed temples and monasteries — the pillars of Tibetan society and religious practice. For Tibetans, the practice of autonomy again dramatically differed from its promise.

Deng Xiaoping reaffirmed Tibet’s autonomous rights — but Li Peng imposed martial law

In the late 1970s Deng Xiaoping walked back the excesses of the Cultural Revolution, and Beijing once more reaffirmed its commitment to Tibetan autonomy. Yet the limited reform measures failed to placate Tibetans. During the 1980s, Tibetans repeatedly protested Chinese rule. Such resistance reached a crescendo in early 1989 via largely symbolic demonstrations led by Lhasa’s monastic community. Rather than acquiesce to Tibetan demands for actual self-governance, China’s leaders again clamped down on Tibet, this time imposing martial law on Lhasa.

For nearly two decades after this turn of events, Tibetan regions within China were relatively quiet. China’s leaders proclaimed such silence to be reflective of a high level of Tibetan satisfaction with their autonomous status. Yet, this narrative was shattered in 2008 when violent protests rocked Lhasa. A wave of Tibetan self-immolations followed, particularly from 2011 to 2013, as protests on Beijing’s policies.

Xi Jinping has been forceful and blunt

Under Xi Jinping, Beijing has relentlessly rooted out all signs of Tibetan unrest in the name of protecting national security. Such an approach is unrelentingly assimilationist — take China’s policy of “Sinicizing” Tibetan Buddhism, for example. My forthcoming article explains this move is intended to impress upon Tibetans the centrality of China to the religion, while branding any resistance to such measures as not only anti-patriotic, but also akin to being heretical. In addition, officials prioritize Chinese language instruction, while increasingly restricting the teaching of Tibetan. Beijing’s actions in Tibet have thoroughly extinguished the limited vestiges of autonomous rule that had managed to survive before Xi’s rise.

Why Tibet’s hollow autonomy matters for Hong Kong

Tibet’s path serves as a foreboding warning for Hong Kong. In parallel to Tibet, Hong Kong has been repeatedly reassured by Beijing that China recognizes its unique characteristics.

However, until now the rooftop of the world and the harbor by the sea have differed greatly in regard to how China’s leaders have responded to dissent in the two regions.

In Tibet, Beijing has repeatedly cast aside the TAR’s autonomy. Since Hong Kong’s return to Chinese rule in 1997, Beijing has been reluctant to overtly violate the Basic Law, and the promise of “one country, two systems” for a 50-year period. Each time Hong Kong citizens have taken to the streets to protest Chinese efforts to circumvent this framework, China has backed off, at least to a degree.

In 2003, Beijing halted its push for national security legislation in Hong Kong under a contested interpretation of Article 23 of the Basic Law, after Hong Kong citizens expressed widespread opposition to such a bill. Hong Kong’s Legislative Council last year withdrew an extradition bill after massive protests against the measure.

Last week’s moves by the National People’s Congress indicates the end of Beijing’s restraint. It also reveals a potentially chilling convergence between what has occurred in Tibet and what is likely to unfold in Hong Kong in coming months and years.

Just as China has imposed more, rather than less, assimilationist policies each time Tibetans protested Chinese rule, Beijing has now set the table to adopt a much tougher response to Hong Kong’s ongoing protest movement.

China’s promise of autonomy in Tibet, Xinjiang and now Hong Kong has always been more canard than safeguard. Such an approach has held China together within the grip of an iron fist. However, Beijing has not been able to force those living on the country’s margins to accept the legitimacy of Chinese governance. What the future holds in store for Hong Kong may already be readily apparent in Tibet’s recent past.

Allen Carlson is an associate professor in Cornell University’s Government Department, the Michael J. Zak Chair of History for U.S.-China Relations, and director of the Brittany and Adam J. Levinson China Asia-Pacific Studies Program.