Aerial video of fleet of warships during Rim of the Pacific Exercise 2014.

PACIFIC OCEAN, AT SEA - JULY 25: In this handout footage provided by U.S. Department of Defense, Forty-two ships and submarines representing 15 international partner nations steam in a close formation during Rim of the Pacific (RIMPAC) Exercise 2014. Twenty-two nations, 49 ships and six submarines, more than 200 aircraft and 25,000 personnel are participating in RIMPAC from June 26 to August 1, in and around the Hawaiian Islands and Southern California. The world's largest international maritime exercise, RIMPAC provides a unique training opportunity that helps participants foster and sustain the cooperative relationships that are critical to ensuring the safety of sea lanes and security on the world's oceans. RIMPAC 2014 is the 24th exercise in the series that began in 1971. (Footage by U.S. Department of Defense/Milmotion via Getty Images)