Primary Functions of the Department of the Army The primary function of the Army is to conduct prompt and sustained combat operations on land to defeat enemy land forces and to seize, occupy, and defend land areas. The Army also provides forces for appropriate air and missile defense and space control operations, including the provision of forces as required for the strategic defense of the United States. In coordination with the other military services, the Army provides forces for joint amphibious, airborne, and space operations. Specifically, the Army develops, in coordination with other military services, doc- trines,  tactics,  techniques,  and  equipment  of interest to the Army. It does that for amphibious operations and space operations not provided elsewhere. The Army also has the primary respon- sibility for developing doctrines, procedures, and  equipment  employed  by  the  Army  and Marine Corps in airborne operations. The Army is trained, organized, and equipped to conduct special  operations,    electronic warfare, and psychological operations. It also operates land lines of communications. The Department of the Army conducts the following activities: — Functions related to the management and operation of the Panama Canal, as assigned by the Secretary or Deputy Secretary of Defense —  The  authorized  civil  works  program, including projects for improvement of navigation, flood control, beach erosion control, and other water resource develop- ments in the United States, its territories, and its possessions — Certain other civil activities prescribed by law Collateral Function of the Army A collateral function of the Army is to train forces to interdict enemy sea and air power and communications through operations on or from land. DEPARTMENT OF THE NAVY The Navy, within the Department of the Navy, includes  naval  combat,  service,  and  aviation forces and the Marine Corps. The Marine Corps includes not less than three combat divisions and three air wings. The Coast Guard, when operating as a service within the Department of the Navy, includes naval combat and service forces and such aviation forces as maybe an integral part of that service. The Navy and Marine Corps, under the SEC- NAV, are responsible for the Navy and Marine Corps  forces  necessary  for  the  effective  pro- secution of war and military operations short of war under the integrated joint mobilization plans. During peacetime the Department of Trans- portation is responsible for maintaining the United States Coast Guard in a state of readiness so that it may function as a specialized service in the Navy in time of war or when the President directs. The Coast Guard may also perform its military functions in times of limited war or defense contingencies, in support of naval component commanders, without transfer to the Department of the Navy. Primary Functions of the Navy and Marine Corps The Navy and Marine Corps are organized, trained, and equipped to conduct prompt and sustained combat operations at sea. They do this to gain and maintain naval supremacy and air superiority in an area of naval operations and to protect vital sea lines of communications. Naval and  Marine  Corps  forces  seize  and  defend advanced naval bases and conduct such land, air, and space operations as may be essential to the prosecution of a naval campaign. The  Marine  Corps  provides  Fleet  Marine Forces  of  combined  arms,  together  with supporting air components, for service with the fleet. It uses them in the seizure and defense of advanced naval bases and for the conduct of such land  operations  as  may  be  essential  for  the prosecution of a naval campaign. In addition, the Marine Corps provides detachments and is organized for service in armed vessels of the Navy and security detachments for the protection of naval property. However, these additional duties must not distract from, or interfere with, the primary organizational operations of the Marine Corps.  These  functions  do  not  contemplate the creation of a second land army. Further, the Marine Corps develops doctrines, tactics, techniques, and equipment employed by landing forces. It does that in amphibious operations of common interest to the Army and Marine Corps. 1-6