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