NATIONAL HARBOR, Md. -- As President Obama endeavors to remake the nation's cybersecurity operations, one of the thorniest challenges he is facing is how to deal with a geopolitical upheaval where foreign enemies route cyber attacks through friendly nations.

Here at research firm Gartner's annual Information Security Summit, David Sanger, the New York Times' chief Washington correspondent, outlined the shaky territory policymakers are venturing into as they embark on the sweeping cybersecurity revamp...