It won't happen.
As soon as we detect missile launches from the ChiComms headed towards US airspace, all Hell breaks loose. They gain some brand-spanking-new, glowing, glass-like parking lots where their major cities used to be, courtesy of our Air Force and Navy. You cannot forget the power of deterrence. It's real; I know........for as a former SAC aircrew commander, I know how the "bad guys" look at our nuclear capabilities.
IOW, it's not "what CAN be done"; it's "what can I do and get away with without seeing my country become a blazing inferno, unfit for human habitation for several centuries".
Launch a missile towards U.S. airspace from China and see if I'm wrong...........
In January, 2001, A commission chaired by Donald Rumsfeld released a report to Congress regarding the vulnerability of U.S. satellites.
I agree that our nuclear stockpile is an excellent deterant. But here's the $64,000 question: Would an attack on our communications network be considered, by whatever administration is in office at the time, this as something that demands a nuclear response? We may have a limited missle defense operational at that time but China may be able to get a couple of birds past it. At this point China is glowing, cratered, radio-active wasteland that no longer has an over-population problem. Gravel from California is pelting Nevada, New Mexico and Oregon. NORAD is scrambling to re-establish communications that were cut off after 90% of U.S. satellites went silent. When the communication satellites went down, the Internet and telephone networks across the country are overwhelmed within minutes. The loss of the GPS satellites add to the communications problem because long-distance and local switches operated by US telecom carriers rely on the GPS network for a timing reference to synchronize their their networks. While all of this is happening, Russia is becoming a little more than upset about the dozen 10 megaton warheads raining down from the heavens so close to their back yard......Well, that's my version of a possible worst case situation. Since you actually served in SAC, I imagine that you would have a more accurate picture of the players and what level of threat they pose to us.