A demonstrator stands beside a mock drone at the gates of Fort McNair where U.S. President Barack Obama was due to speak at the National Defense University in Washington May 23, 2013. Obama gave a robust defense on Thursday of U.S. use of unmanned armed drones and said the threat of terrorism to the United States had shifted since the attacks on September 11, 2001. REUTERS/Kevin Lamarque (UNITED STATES - Tags: POLITICS MILITARY TPX IMAGES OF THE DAY) - RTXZY9F
REUTERS
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