U.S. Defense Secretary Chuck Hagel escorts Yemen's President Abdo Rabby Mansour Hadi, who signs the guestbook during his visit to the Pentagon, July 30, 2013. U.S. Defense Secretary Chuck Hagel escorts Yemen's President Abdo Rabby Mansour Hadi, who signs the guestbook during his visit to the Pentagon, July 30, 2013. SHARE IMAGE: Download Image: Full Size (0.63 MB) Tags: Photo Essays Photo By: VIRIN: 049236-Z-ZLQ84-261.jpg Photo Gallery