I seriously doubt that many of the buildings in the United States have been built to the new standards to withstand earthquakes. I believe an 8.8 would be devastating. The damage would be so severe that there would be few structures left standing. The number of people killed or injured would be in the thousands. Any aftershocks would probably cause more damage and injury from the rubble resettling.
The United States is a very large country and most earthquakes are regional in nature, no matter how large they are. While an 8.8 earthquake is a very serious problem, and it would cause a lot of damage whereever it struck, it would not destroy a whole country. After all, the earthquake/tsunami combination in Japan hurt the country quite a bit but did not destroy it.
No, I do not believe that an earthquake with an 8.8 magnitude would "shake society to its knees." We humans have proven to be a very resilient species. While there would be some massive amount of injury and misery, we would undoubtedly pick ourselves up, dust ourselves off, and start again. That's what we do.
An earthquake with an 8.8 magnitude is quite powerful and destructive and it would certainly change a lot about society in a matter of seconds. The one wonderful thing I've noticed about natural disasters, however, is the fact that people often ban together and try to help each other during these times so I don't know that it would actually bring society to its knees.
If we had an earthquake at this magnitude, it would be horrible for sure, and it would level a lot of buildings, but it would not bring society to its knees. We are good about seeing the light at the end of the tunnel and rebuilding what we lost and coming back.