(including manpower, logistic, and mobility support) and assesses the effect of such deficiencies and strengths on meeting national security objectives and policy and on strategic plans. He or she establishes and maintains  a  uniform  system  for  evaluating  the preparedness of each unified combatant command to carry out assigned missions. The chairman advises the SECDEF  on  the  priorities  of  the  requirements identified by the commanders of the unified combatant commands. He or she determines the extent to which program recommendations and budget proposals of the military departments and other DoD components for a fiscal year conform to priorities established in requirements of the unified combatant commands. He or she is responsible for submitting to the SECDEF alternative program recommendations and budget proposals, with guidance provided by the SECDEF, to achieve  greater  conformance  with  priorities established by the unified combatant commands. The chairman also advises the SECDEF on the extent to which major programs and policies of the armed forces in the area of manpower conform to strategic plans and assesses military requirements for defense acquisition programs. Additionally, the chairman:    Formulates doctrine and training policies and coordinates military education and training    Represents  the  United  States  on  the  Military Staff Committee of the United Nations    Performs such other duties as may be prescribed by law or by the President and the SECDEF    Convenes and presides over regular meetings of the Joint Chiefs of Staff    Assists   the   Joint   Chiefs   in   carrying   on   their business as promptly as practicable    Schedules  issues  for  consideration  by  the  Joint Chiefs The chairman, while so serving, holds the grade of general or admiral and outranks all other officers of the armed  forces.  The  vice  chairman  of  the  Joint  Chiefs performs  duties  assigned  by  the  chairman,  with  the approval  of  the  SECDEF.  The  vice  chairman  acts  as chairman  when  there  is  a  vacancy  in  the  office  of  the chairman   or   in   the   absence   or   disability   of   the chairman. The vice chairman, while so serving, holds the grade of general or admiral and outranks all other officers of the armed forces except the chairman of the Joint Chiefs of Staff. The  Joint  Staff  under  the  chairman  of  the  Joint Chiefs of Staff assists the chairman and, subject to the authority  of  the  chairman,  the  other  members  of  the Joint   Chiefs   of   Staff   in   carrying   out   their responsibilities. The Joint Staff is headed by a director who  is  selected  by  the  chairman  in  consultation  with the other members of the Joint Chiefs of Staff, and with the approval of the SECDEF. Officers assigned to serve on   the   Joint   Staff   are   selected   by   the   chairman   in approximate   equal   numbers   from   the   Army,   Navy, Marine   Corps,   and   Air   Force.   The   Joint   Staff   is composed  of  all  members  of  the  armed  forces  and civilian  employees  assigned  or  detailed  to  permanent duty to perform the functions assigned to the chairman of the Joint Chiefs of Staff. Unified Combatant Commands The   unified   combatant   commands   are   military commands   with   broad   continuing   missions   for maintaining  the  security  and  defense  of  the  United States  against  attack;  supporting  and  advancing  the national policies and interests of the United States and discharging U.S. military responsibilities in their area of   responsibility;   and   preparing   plans,   conducting operations,  and  coordinating  activities  of  the  forces assigned  to  them  in  accordance  with  the  directives  of higher authority. The unified combatant commands are part of a military Unified Command Plan subject to the direction  of  the  President.  The  commanders  of  the unified   combatant   commands   exercise   command authority   over   forces   assigned   to   them   under   the authority,  direction,  and  control  of  the  SECDEF,  also subject to direction of the President. The latest change to  the  Unified  Command  Plan,  signed  by  President Clinton  September  30,  1999,  changed  missions  and replaced  the  U.S.  Atlantic  Command  with  the  U.S. Joint Forces Command. The change also included the mission  to  assist  civil  authorities  in  the  event  of  an attack   or   accident   involving   weapons   of   mass destruction and to strengthen the United States’ ability to   counter   cyberwarfare.   The   operational   chain   of command  runs  from  the  President  to  the  SECDEF  to the commanders of the unified combatant commands. The  chairman  of  the  Joint  Chiefs  of  Staff  functions within  the  chain  of  command  by  transmitting  to  the commanders  of  the  unified  combatant  commands  the orders of the President or the SECDEF. Subject to the authority,  direction,  and  control  of  the  SECDEF,  the chairman  of  the  Joint  Chiefs  of  Staff  serves  as  the spokesman   for   the   commanders   of   the   unified combatant  commands,  especially  on  the  operational requirements   of   their   commands.   The   unified combatant commands are as follows: 5-4