Secretary Panetta and former Secretary Gates share a laugh Secretary of Defense Leon E. Panetta, right, and former Secretary of Defense Robert M. Gates, left, share a laugh at the portrait unveiling ceremony for Gates at the Pentagon on Oct. 29, 2012. Gates was the 22nd secretary of defense. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 436744-G-MGS25-963.jpg Photo Gallery