John Costello is the Chief of Staff at the Office of the National Cyber Director and an Adjunct Senior Fellow with the Technology and National Security Program at the Center for a New American Security.  Previously, Mr. Costello has served in a number of roles in the U.S. Government, including as the Deputy Executive Director of the Cyberspace Solarium Commission and the Deputy Assistant Secretary of Intelligence and Security at the Department of Commerce. Mr. Costello also served as the Director of Strategy, Policy, and Plans and Senior Advisor to the Director of the Cybersecurity and Infrastructure Security Agency. Mr. Costello was an enlisted U.S. Navy sailor and has a working professional proficiency in Chinese Mandarin, graduating with honors from the Defense Language Institute. Mr. Costello’s fellowship will be focused on improving U.S. government collaboration with information and communications technology service providers on cyber defense and security.