Re: Enforce their walls.
@ShadowSystems - Don't forget the Silk Road. You could view Chinese history as a pendulum between isolationism (Great Wall) and trade (Silk Road). Isolationism was winning in the 19th century, until a bunch of state-backed drug-dealers broke in, it made a comeback in the early communist era but receded with the 1970's Opening of China. Now the controls are being strengthened again.
Note that the pendulum is largely driven by forces within China. Good luck resisting a China-approved internet ("excise a cancerous growth", as you put it) when you're buying all your manufactured goods, including electronics, from China.
Biting the hand that feeds IT
