U.S.-Estonia Vision Kathryn Wheelbarger, acting assistant secretary of defense for international security affairs, right, and Kadi Silde, Estonia’s undersecretary of defense for policy, sign the U.S.-Estonia Vision of Security Cooperation at the Pentagon, May 22, 2019. SHARE: Download: Full Size (5.17 MB) Tags: Lithuania, Under Secretary of Defense, wheelbarger Credit: Army Sgt. Amber I. Smith, DOD VIRIN: 190522-D-SV709-0003.JPG Photo Gallery