FINAL DAY Two P-3 Orion anti-submarine and maritime surveillance aircraft from the Japan Maritime Defense Force, left, and the U.S. Navy, right, fly over the attack submarine USS Houston on the final day of Keen Sword, an exercise in the Pacific Ocean, Dec. 10, 2010. The bilateral exercise is designed to strengthen military operations between the U.S. and Japan, which remains a key strategic partner in the northeast Asia-Pacific region. SHARE IMAGE: Download Image: Full Size (0.07 MB) Photo By: VIRIN: 611358-W-NJI27-990.jpg Photo Gallery