The United States Navy

"The development of aircraft, weapons, tactics, technique, organization, and equipment of naval combat and service elements".
U.S. Navy training manuals state the mission of the U.S armed forces is "to prepare and conduct prompt and sustained combat operations in support of the national interest". As part of that establishment, the U.S. Navy's functions comprise sea control, power projection and nuclear deterrence, in addition to "sealift" duties.