It's difficult to attack well-designed and maintained computer systems and it's impossible to secure poorly designed systems connected to the Internet.
When the insecure junk we call our county's critical information infrastructure gets seriously attacked, the attack comes from botnets operating in every country including our own. To "fight back" we must destroy every insecure computer on the internet!
What will be left standing? Oh, most OpenBSD systems. Quite a number of well administered Unix and GNU/Linux systems. But will we still have electricity to run them? How much of the infrastructure of the Internet itself will still be left after the war has taken out insecure routers, switches and the DNS system?
My critical resources run on OpenBSD servers behind ghost firewalls. My less critical resources are run under GNU/Linux with liberal use of virtualization and sandboxing. There are a few ways I can still be attacked but then, I'm only securing one geek's home office!
There's nothing to be gained from fighting a cyber war. There's no sane alternative but to secure our infrastructure properly right away.