Quietly and without much public recognition, the National Guard has been developing a sophisticated capability for cyberdefense. A few weeks ago I was on Capitol Hill at an event sponsored by the Lexington Institute discussing the growing role of the National Guard in protecting the nation’s critical infrastructure from cyberattacks — specifically the electric power grid. Risks to US critical infrastructures are growing significantly; the Department of Homeland Security reported a seven-fold increase in cyber incidents on critical infrastructures between…