That assumes that we simply don't cut China out of our Internet linkages,
that wouldn't prevent inside USA cyber terrorists but we could isolate China at any sign of them employing cyber terrorism.
Why think the US refuses allow international control of internet? We would lose our ability to control who uses internet, "delete china" and cut all links, cut any links to europe etc if they don't cut theirs to china, we could isolate internet if necessary to just USA ISP's and drop all linkage to anything outside USA.
Fact is within my ISP's spam blocking I block all chinese/asian based domains, I get too much spam crap from such domains so I domain block them.
It's not nearly as easy as you propose, and if the attack were done pre-emptively and correctly, it wouldn't matter.
The infamous Solar Sunrise attack of 1998 compromised information on thousands of Defense Department computers during a period where the Pentagon was preparing for a possible strike in Iraq. The government had to answer for that, and its the only real reason the JTF-GNO was even created. The real problem with the US is that we require Pearl Harbors in order to make any major changes. Look at all the changes after 911. Solar Sunrise just wasn't known to or understood enough by the public to warrant bigger result. But its only a matter of time before a much larger "Cyber Pearl Harbor" attack happens. And the Chinese, for one, are already setup to do precisely that if they so choose.
Our own capabilities in these regards are 99.9999% classified. Even Area 51 doesn't suffer that extent of severe classification anymore and thats kind of scary to me. Virtually the only public piece of information known (beyond info on the JTF-GNO itself) is that only the President or the Secretary of Defense can authorize an Offensive Hacking or DOS Attack against a foreign entity.
The targets are vast:
For Military alone, attempt to deny an enemy use of is own computer networks in wartime, change critical information (preferably without the enemy even realizing), or trick the enemy entirely into thinking something has happened, or is happening that is not, etc. etc. Then there are the financial, political, or purely economic targets and effects. A powerful, and more importantly, CHEAP new kind of weapon.
Air Force Deputy Director for Information Warfare Col. Chris "Bulldog" Glaze was quoted as saying "I've got to tell you we spend more time on the computer network attack business than we do on computer network defense because so many people at very high levels are interested in developing the policy for
it"
How do you defeat a country so reliant on advanced technology? Not by shooting at it with bullets thats for sure. Thank God some in our government have taken note of that, though more funding needs to be provided for defense and not just the "cool new cyber weapons". Guess the warmongers in Washington love having fancy new weapons more than anything else. [:D]
Anyway, if there ever is a war between the US and China... this is the kind of stuff thats going to end up being most important...
Warfare has evolved a lot in the last century. Even Naval Power could be near to completely obsolete given certain changes and enhancements to Air Power and Operations. And ultimately, with the amount of computers and technology involved, the real winners will be those who can weild the type of weapons that nearly literally "virtually destroy" an enemy unit rather than necessarily physically destroying it.
One somewhat radical Sci-Fi example would be akin to how knocking out the Droid Control Ship in Star Wars Episode I rendered the entire droid army utterly useless...
And, of course, as bad as the effects could be now.. Imagine how much worse in 10 years when we start using unmanned drone aircraft exclusively for delerving death to the enemy.....