Vice Admiral Scott Swift (4th L), Commander of the US Seventh Fleet and Rear Admiral Thomas Carney (C) pose with Vietnamese army officers at the end of a welcoming ceremony to mark the port call of three US naval ships in the central city of Danang on April 23, 2012.  Vietnam and the US will hold five days of "non-combatant" naval exchane activities next week in the port city of Danang amid rising tensions in the South China Sea with China whose authorities have just released 21 Vietnamese fishermen who were detained seven weeks ago near disputed islands in the South China Sea, drawing strong protests from Hanoi.   AFP PHOTO/HOANG DINH Nam (Photo credit should read HOANG DINH NAM/AFP/Getty Images)