Following the failure of the latest round of peace talks, the North Koreans have been taking increasingly provocative actions that have further inflamed tensions in the region. These actions began three days ago when a series of cyber attacks struck utilities across the Republic of Korea. In particular, the power grid in Seoul was repeatedly attacked resulting in a blackout. Power has still not been fully restored, in part due to insufficient replacement parts being on hand. Intelligence estimates point to a repackaged version of Stuxnet being used to attack still vulnerable industrial control systems. The blackout is causing substantial economic damage as well as a burgeoning humanitarian crisis. You are the Director of the National Security Office. What actions would you recommend to President Moon Jae-in that Korea take in response, including how best to deter North Korean aggression such as by hardening Korean critical infrastructure systems against any future cyber attacks?