BANGKOK — Much of the world is captivated by protest scenes in Hong Kong, where massive crowds risk Beijing’s wrath.

But perhaps no foreign observers are as riveted as veterans of China’s 1989 uprising, which ended in bloodshed near Beijing’s Tiananmen Square.

That youth-led movement has been widely regarded as the most formidable challenge in history to the Chinese Communist Party’s iron rule. It ended in a gruesome crackdown. Estimates of the death toll range from a few hundred to a few thousand. The violence and ensuing manhunt sent student organizers fleeing into exile around the globe.

They are now pushing 50, but many have never dropped their pursuit of a freer, less authoritarian China. Their dream has been revitalized by Hong Kong’s uprising, which has mobilized tens of thousands of people to peacefully blockade roads.

Hong Kong’s protesters demand the right to elect the island’s top official. China has conceded to elections in 2017 with a major caveat: only up to three candidates, pre-approved by a pro-Beijing committee, can run. One Hong Kong blogger who supports the protesters compared the situation to parents who give their son “the freedom to choose your own bride” yet limit his choice to two pre-selected women.

Veterans of the Tiananmen movement have expertise in this rare field of rising up against the Chinese state. GlobalPost contacted two prominent leaders from the Tiananmen protests to ask how Hong Kong’s demonstrators might prevail in this face-off.

Wu’er Kaixi was once No. 2 on China’s list of most-wanted student leaders. Now 46, he’s a prominent commentator living in Taiwan. He is known for boldly chastising China’s powerful premier in a televised meeting between students and officials. (“You leaders just don’t get it,” he told Premier Li Peng in 1989.)

Zhou Fengsuo was once No. 5 on China’s most-wanted list. Now 47, he is located in San Francisco and works as a financial analyst and activist. Zhou co-founded Humanitarian China, a US nonprofit supporting Chinese dissidents.

Both said Hong Kong’s current student leaders are ideal heirs to their struggle. “They’re the best I’ve seen since 1989,” Zhou said. “They are China’s hope.”

These are their suggestions, edited for brevity and clarity, to Hong Kong’s protesters.

1) Never underestimate Beijing

Wu’er: There’s a genuine possibility the Chinese regime will go from stupid to more stupid. Violence is a possibility ... and nobody is really ready for a tough response. Not unless you were brought up in the middle of a war zone.

We weren’t ready [for a massacre] at all. When the violence came, we were forced to make up our minds instantly at that moment. The Hong Kong people are facing that too.

Zhou: I think they’re facing the worst totalitarian regime in human history. It starved 30 million people to death and used tanks on its own people. We should not underestimate the evil tactics that the government will use.

2) Don’t go on a hunger strike

Zhou: Personally, I don’t like that kind of strategy. We should protect our young people. Let’s protect their strength. This fight could go on for a month or a year. Maybe years! We need to prepare for that ... because occupying the streets is very demanding. It demands a lot of physical and spiritual strength.

3) Actually, a hunger strike might help

Wu’er: The hunger strike in 1989 served several purposes. Number one: there was a focus within the movement. Number two: it really stirred emotional powers in people. Number three: for the hunger strikers, who numbered around 3,000, it was easier for them to make decisions — to charge forward, to withdraw — and the rest could follow.

I’d urge them to think about a hunger strike. Actually, I’ve already offered this advice to them. ... In 1989, we proved it didn’t weaken us at all.

4) To understand Beijing, study Tiananmen. The riot police pullback is a dangerous sign

Zhou: It’s unfolding exactly like in 1989. The government is doing similar things, like withdrawing the riot police. In 1989, two weeks after they declared martial law, they withdrew army troops. They were planning for an attack that was the eventual massacre.

So Beijing must be planning some counterattack ... if history is any measure, it may happen. The government is the same.

5) Maintain specific demands, and avoid vague calls for “democracy”

Wu’er: It will be very important for them to stay focused and stick to very specific demands. But they know this better than I do. The organizers of this movement — although it’s their first time — they’re from a very sophisticated society. Cool-minded people are behind this.

6) Ensure order within your ranks

Zhou: When we’re on the streets, we must keep the streets safe. This may be a tough challenge, even when citizens are supportive. This will be an issue that the protesters need to think hard about and work hard on. They need to keep order on their streets.

7) Ignore those who call you naive

Wu’er: The world is so forgiving when it comes to China. They say, ‘Eh, it’s China. What can you do?’ That type of mentality helps Beijing. They think the world will tolerate their absurdity because they’re so accustomed to it.

The world will point fingers at those who didn’t see this coming and say, ‘You’re the one who’s absurd because you didn’t see that the communist party would deploy troops.’ If China goes to the extreme, then it’s extreme. Let’s not forget that simple fact. No one should have to accept it.