As Taiwanese students stormed the Legislative Yuan to protest against a trade pact with the mainland, the chant rang out: "Today's Hong Kong, tomorrow's Taiwan!" The slogan caused mixed feelings in Hong Kong and troubled Beijing. Could it be that "today's Taiwan" - protests and all - will actually be "tomorrow's Hong Kong"?
There is no end in sight to the weeks-long protest initiated by students in Taipei, but many are drawing comparisons between what's going on there and the planned Occupy Central pro-democracy protests here - even though they may prove as different as apples and oranges.
One interesting point is that contacts between protesters have mostly involved students from both sides. Occupy organisers have reiterated their intention to protest peacefully while pan-democrat lawmakers are perhaps more occupied by their invitation to Shanghai to discuss electoral reform; few have visited Taipei so far.
It's possible that the pan-democrats' caution reflects a realisation that an earlier visit to Taipei to learn about protest from a pro-independence figure was a bad idea. Beijing severely attacked that visit, and local Beijing loyalists declared it "politically unwise". While pan-democrats argued that the visit was merely a study tour, they also realised that the idea of independence for Taiwan never went down well in the city.
Whatever the conclusion of the Taipei protest, its impact on Hong Kong is obvious. Besides raising questions about Occupy Central, it gives cause for reflection on Hong Kong's role in Beijing's Taiwan policy.
For decades, the "one country, two systems" principle for Hong Kong has carried another mission: to convince the people of Taiwan it would work for them, too. However, far from making a convincing case, the example of Hong Kong has been cited by those who oppose the trade pact, who warn that Taiwan would come to rely too much on the mainland, much as Hong Kong does today. Of course, some in Taiwan support the agreement and believe it creates a win-win situation.
But whatever happens in Taiwan, Beijing long ago realised it could not cite Hong Kong as a model for the cross-strait relationship and seldom mentions it in talks with Taipei.
Instead, Beijing keeps a very close eye on certain "Taiwan influences" that may penetrate Hong Kong. The central government also restricts exchanges between Hong Kong and Taiwan, insisting they be "non-official" in nature, except with its prior approval.
Hongkongers have mixed feelings about Taiwan: while many envy its democratic elections, scenes of violence and disruption in the legislature raise eyebrows. And the latest protests gave pro-establishment lawmakers a new worry. They fear the Legislative Council building would prove impossible to defend if Occupy Central got out of control.
A contingency plan will be discussed, but there is a more general concern: even if protest organisers vow peaceful means, can they be sure radicals will not take control?
Still, Hong Kong and Taiwan differ in many ways. Beijing and the people of the two places know that. While neither is likely to be the other's tomorrow, they can learn from each other.