Massive arms sales from the U.S. for sure. I agree with you here. The right kind of cyber attack on our infrastructure could be almost as devastating to this country as a nuclear attack (minus the radiation sickness and big hole at ground zero). We are too connected financially, infrastructure wise and to things people do not think much about like hospitals, emergency services, etc. There really is nothing much today that could not be brought down or interrupted by a real cyber attack. For all the electronics on my vessels, I still damn sure know how to navigate the old way for a reason.
the only way to prevent a cyber attack is to use 'tempest' requirements for your computing facilities / systems
a way that is almost as good is not to tie your computer system to a phone line
alternately, if you must have a phone line, use a system where a user calls in and they input their id and hangup and the system calls them back at a known phone number
of course nothing but very tight physical security will prevent someone downloading data to a storage media and walking out the door with it...