An effective defense would need many layers of  “countermeasures designed to foil intruders once they’ve broken in” (Arquilla 2).  These countermeasures would include disguising important data (i.e. making critical data look like supply orders) and incorporating the latest in encryption technology, which would keep the intruder from reading the information they do see (Arquilla 2).  
    Another possible way to protect the nation would be for the government to employ some of the best hackers.  Only the best hackers can tell you if you’ve designed a system that is very difficult for them to disrupt (Arquilla 3).  However, these defenses aren’t guaranteed successful.