Four words that doomed Hong Kong
One country, two systems.
This was the four-word principle created by China's former leader Deng Xiaoping in the early 1980s.
The proposition was simple enough: there would be one overarching "country" - the People's Republic of China - but Chinese territories like Hong Kong and Macau would retain a "high degree of autonomy" with their own special economic and administrative "systems".
While officially united under the mainland, these regions would have their own government, separate legal and economic systems, and Hong Kong would serve as a vital trade route between mainland China and the rest of the world.
But in 2019, this vision hasn't translated. In recent years, Beijing has become increasingly aggressive in its push for "one system for all" - and Hong Kong is determined not to go down without a fight.
WHY DIDN'T THE AGREEMENT WORK?
The past few months of protests in Hong Kong have become increasingly violent and drawn growing public ire from the mainland.
The success of the one country, two systems agreement rested on the good-faith assumption the Chinese Communist Party would allow Hong Kong to maintain its autonomy without interference until 2047.
Instead, we've seen repeat incidents of Beijing undermining it.
In 2003, Hong Kong's first chief executive, Tung Chee-hwa, attempted to push through a national security law that many in the territory - including pro-democracy campers, lawyers, journalists and human groups - feared was aimed at silencing free speech.
More than half a million people protested the move, ultimately sparking a crisis of governance, and the bill was withdrawn.
In 2012, when the government tried to introduce a reformed curriculum plan of Chinese "patriotic" education into Hong Kong schools, a similar outcry followed.
The new education model would have bolstered the Chinese Communist Party in classrooms while whitewashing controversial moments like the Tiananmen Square massacre. Thousands took to the streets in protest.
Then came the well-documented "Occupy Movement" of 2014 in which young protesters took to the streets demanding political reforms and the right to elect their own chief executive - one with no ties to Beijing.
In 2015, there was an international outcry after five staff at Causeway Bay Books - an independent publisher - mysteriously disappeared. It was suspected the Hong Kong citizens had been abducted by Chinese authority figures - a suspicion that was later confirmed.
More recently, the attempt by Hong Kong's embattled leader Carrie Lam to push through an extradition bill that would allow criminal suspects to face trial in mainland China sparked the protests you're seeing today. They have now been running for 11 straight weeks and are broadly against Beijing's control.
In other words, one country, two systems wasn't exactly honoured by China for long.
WAS THE AGREEMENT 'DOOMED TO FAIL'?
Some critics have argued one country, two systems was never going to work in the first place.
Keith Richburg, a journalism professor at the University of Hong Kong, said it was "always doomed to fail" due to the fundamental political differences between the two regions - authoritarian China and liberal Hong Kong.
"Never before had an autocratic, communist-run, single-party dictatorship peacefully absorbed a modern, sophisticated, quasi-democratic capitalist territory," he wrote in The Washington Post. "Never before had a people who had enjoyed free speech, freedom of assembly, a free flow of information and limited free voting voluntarily relinquished those rights to merge with a country where such freedoms were often ruthlessly suppressed."
He argued its success rested on a "willing suspension of disbelief" - sitting back and pretending China's communist rulers were going to allow this.
But Adam Ni, a China researcher from Macquarie University, said the model wasn't seen as an inevitable failure from the get-go. Rather, it failed because 21st-century Beijing refused to honour the agreement.
"I don't think it was destined to fail," Mr Ni told news.com.au. "There were fundamental political differences between Hong Kong and the mainland, but I think at times of negotiations things were still up in the air regarding the trajectory of the PRC and whether it was going to liberalise.
"It was only around the mid-2000s that the pendulum swung the other way towards more suppression and control.
"Today we can clearly say that's the road the PRC went down, but back in the '80s and '90s the West was hoping to move it in a more liberal direction by engaging with the PRC."
Mr Ni noted the system was never going to last forever. Even the prospect of Hong Kong remaining semi-autonomous until 2047 - as agreed during the handover - was dubious.
"The Chinese Government was only going to allow one country two systems as an interim measure for integrating Hong Kong into the PRC's political system, and we've seen China trying to accelerate that," he explained. "It was a means towards an end of negotiating to get Hong Kong until it could get away with not adhering to the plan.
"Beijing's long-term aim is to integrate Hong Kong into the PRC's political systems and essentially rule the people as it does the mainland."
He also said other major aspects of China's rise - the increasingly repressive direction of its government, and the rapid growth in its economic and military power - have contributed to Beijing's aggressive pursuits in Hong Kong.
WILL CHINA'S ARMY INVADE HONG KONG?
The protests in Hong Kong have been running for 11 straight weeks.
Over that time, the Chinese Communist Party has shifted from ignoring the demonstrations to weaponising them with its state media propaganda.
This coverage - which has included unfavourable documentation of the protests and footage of large-scale military exercises being conducted at the China-Hong Kong border in Shenzhen - has sparked speculation Beijing will deploy its army into the territory.
But experts say this is highly unlikely at this stage.
"I think China's state media is posturing - it's trying to send a deterrent message and stop momentum for the protests," said Mr Ni. "I don't think Beijing is willing to use that kind of force yet."
He said this is partly because the cost for Beijing would be too high - both economically and in terms of its international reputation.
"This is a political problem, not a security problem. These are not terrorists or criminals, no matter how much the Chinese Communist Party labels them as such. They're aggrieved people with demands. Sending in the military is just not the right solution to the problem - it's just going to create long-term resentment."
But Mr Ni pointed out Beijing already had intervened in a number of ways - from encouraging Hong Kong police to get tougher with protesters to targeting major Hong Kong companies like its flagship airline and the Big Four accounting firms.
In an earlier interview with news.com.au, Dr Malcolm Davis, a senior analyst at the Australian Strategic Policy Institute, said Mr Xi would hold off until at least October 1, which will mark the 70th anniversary of the founding of the People's Republic of China.
In the lead-up to this milestone, Mr Xi has arranged for a massive display of military strength on Tiananmen Square. Deploying People's Liberation Army troops to Hong Kong before that date would detract from this.
WHY IS HONG KONG PROTESTING?
The demonstrations started as a protest against a proposed extradition bill that would send criminal suspects China but have since become more widely about opposition to the mainland's growing political influence overall.
When Hong Kong was handed over from Britain to China in 1997, it was agreed the territory would be allowed to maintain its unique freedoms and civil liberties for the next 50 years - a deal the protesters believe has not been honoured by Beijing.
The protesters believe China has gradually been whittling away their liberties since the handover, including by suppressing the "Umbrella Movement" in 2014 and by kidnapping the five Hong Kong booksellers.
With the ongoing protests, they are now pushing for the right to directly elect their own government, for an independent commission to investigate police brutality, and they want the territory's leader, Carrie Lam - who was hand-picked by the Chinese Government - to resign.