It's interesting to see the zeitgeist of this evolve. Just 6 months ago much of the public was very blasé about China, but experts in many realms were sounding alarm bells. A few months later, now look at it.
This is how systems exhibiting punctuated equilibria evolve.
The physical analogy is a pile of sand, accruing by one grain at a time. It will eventually collapse, that is known. And it will do so suddenly, anyone who made sandcastles knows this. But knowing when it will collapse is strikingly tough.
With sand, the correlation comes from friction between grains. With people, the correlation comes from social pressure. Once the friction is overcome, the social pressure breached, the system changes rapidly.