The Chinese communist government must be feeling a sense a deja vu as Hong Kong’s democracy protests gather strength. It was 30 years plus two months ago this summer that pro-democracy protesters gathered and then became a force on Tienanmen Square in Beijing. That protest saw peaceful Chinese citizens camp and sing and build a likeness of the Statue of Liberty to symbolize their quest for the freedoms we all too often take for granted: freedom of speech, freedom of assembly, freedom of religion, freedom of the press, the freedom to be left alone.

The ChiComs will surely have those events in Beijing in mind, but also events that played out that same year in Europe in mind as well. As I wrote a few weeks back, 1989-90 was a watershed in geopolitics. Communists in Beijing and Moscow took very different approaches to pro-democracy protests at that time. The Soviet Union allowed a trickle through the Berlin Wall in November 1989 to become a river, and then a torrent that emptied the Soviets of their power. The Soviet Union was dead by 1991.

China took a different approach. It cracked down hard on its protesters in the summer of 1989. The communists sent in the so-called People’s Liberation Army. It crushed the protests on June 4-5, 1989, killing as many as 10,000 of their own citizens. While the world condemned China’s actions, its communist regime survived, while the Soviet government and its satellites did not.

As China ponders a repeat of 1989, it faces a different world, and on different soil.

How is Hong Kong different from Tienanmen Square?

Hong Kong is not Beijing by any stretch. It was culturally separated from mainland China by British rule for 156 years, ending in 1997. Hong Kong has a strong living memory of benign if not benevolent British rule that includes numerous freedoms not enjoyed by mainland China, including freedom of speech and the press. Since 1997 those freedoms have been gradually curtailed by mainland influence and rule. But the attempt to pass a law allowing Hong Kong citizens to be extradited to China’s injustice system and its prison archipelago sparked the current protests. Hong Kong’s Beijing-approved chief executive, Carrie Lam, went into temporary hiding. That law has been tabled but not abandoned, which has only fueled the protests. They have grown from being about that law to being about freedom in a more general sense. The protesters, echoing 1989’s “Goddess of Democracy,” have started flying the American flag and singing the American national anthem — fully aware of how that will be read in Beijing and around the world.

Hong Kong is also relevant to the world markets and world travel in ways Beijing was not in 1989. It has its own vibrant stock index with a market cap of nearly $30 trillion. It is home to one of the busiest airports in the world (which protesters shut down this week). World media all have bureaus or at least correspondents on the ground in Hong Kong. It is a major world travel destination and a cultural hub thanks in part to its movie industry. Therefore any action Beijing takes against Hong Kong will impact markets, and will be much more visible to the outside world than Beijing was 20 years ago.

How will social media portray events?

In 1989, there was no YouTube. There was no Facebook. Or Twitter. Or any other social media. Once the PLA moved in on the protesters in 1989, darkness fell on the square. The outside world had no vantage from which to witness events. We caught glimpses in the “tank man” and a few other events, but had no comprehensive information stream until the blood had been shed. The condemnation of China that followed was often devoid of emotion, at least partly because we did not see what had happened.

2019 is an entirely different world. Social media has proliferated and the protesters are using it to great effect. But. YouTube, Google, Facebook, and Twitter have all been collaborating with the ChiComs and bowing to pressure to censor content there. They have even reportedly helped China craft its “social credit score” — a digital means of reinforcing oppression at an entirely new personal level. Will they censor content coming out of Hong Kong? So far they have not. That might change if Beijing leans on them hard enough. Just this week, Versace, Coach, and Givenchy have bowed to pressure and groveled over a T-shirt design. Will the left-dominated social media giants do the same? The safe bet is yes, they will.

How will China’s neighbors and the United States react?

Among the countries watching Hong Kong will surely be Japan and South Korea, both U.S. allies, along with Taiwan, Vietnam, North Korea and pretty much every other country in the region. How the United States responds will be of extreme importance. President Donald Trump has already engaged China directly in a trade war, pitting the world’s #1 and #2 economies against each other. Trump has also spoken out for human rights and unlike his Democratic predecessor, has never voiced approval for China’s appalling “one-child” policy. It’s fair to say China already views him as an adversary. Trump also surely has connections to the thriving Hong Kong business sector. But if China uses force, what will Trump do? And how will our allies in the region and around the world respond?

What will North Korea make of it all? China is still its largest benefactor. If China cracks, if the protests spread beyond Hong Kong as they might, communist dominoes could fall just as they did when the Berlin Wall turned from a trickle to a gush in 1989. The Kim cult will surely see imminent danger in events in Hong Kong.

How important is Hong Kong’s fate?

Hong Kong by itself is an important commercial power and trading hub, as it has been for centuries. The outcome of these protests will spread far beyond the city-state, for good or ill. If China crushes the protests, Hong Kong’s special status effectively ends and its people lose their basic human rights.

But Hong Kong could conceivably bring about a weakening or even ending of communist rule in mainland China – saving Taiwan and Macao from eventual invasion to “reunify” them to the mainland, and possibly staving off the next world war — as the USSR’s collapse ended the Cold War. That’s what those American flag-waving protesters have in mind. But Beijing has that same outcome in mind as well.

Update: The post originally said Tienanmen Square was 20 years ago. This has been corrected to 30.