I doubt it. China gets a lot of business from overseas via the Internet. Think about all those fabs where you upload a PCB design and for $2, they manufacture it and mail them to you. If Americans could not visit the Chinese Internet, those companies would be out of business overnight. When nobody has a job or money, people start questioning the government, which the government would probably like to avoid.

The reality of China is that they need the global economy as much as the global economy needs them. No one entity can really pick up their ball and go home, as much as China would probably love to.