If a Civil War kicks off, I'll be you ever dollar I got that, China, Iran, Russia, etc will all make their moves. China/Russia may well invade us thru California while Iran/Israel + Saudia Arabia start duking it out with nukes in the Middle East. The best thing to do will be to hunker down for a year while the dust settles...
If we have a president who is a "New World Order" advocate at the time of rebellion, China and Russia may be invited in as part of a U.N. contingent to establish order. The U.S. military could find it hard to open fire on fellow countrymen, so U.N. "peacekeepers" could be called on to do the job. U.S. troops will be busy tending to problems in other nations.