Glenn Gerstell, who spent much of the last five years pounding a steady drumbeat warning of a global cyber pandemic, has left his job as general counsel at the U.S. National Security Agency. His last day was Jan. 31.

Gerstell will be a senior adviser at the Center for Strategic & International Studies in Washington, D.C., beginning this month. The center, a nonpartisan think tank on global challenges, was not immediately able to provide a start date.