((a)) When a function, power, or duty or an activity of a department or agency of the Department of Defense is transferred or assigned to another department or agency of that department, balances of appropriations that the Secretary of Defense determines are available and needed to finance or discharge that function, power, duty, or activity, as the case may be, may, with the approval of the President, be transferred to the department or agency to which that function, power, duty or activity, as the case may be, is transferred, and used for any purpose for which those appropriations were originally available. Balances of appropriations so transferred shall—
((1)) be credited to any applicable appropriation account of the receiving department or agency; or
((2)) be credited to a new account that may be established on the books of the Department of the Treasury;
((b)) When a function, power, or duty or an activity of a department or agency of the Department of Defense is transferred to another department or agency of that department, those civilian employees of the department or agency from which the transfer is made that the Secretary of Defense determines are needed to perform that function, power, or duty, or for that activity, as the case may be, may, with the approval of the President, be transferred to the department or agency to which that function, power, duty, or activity, as the case may be, is transferred. The authorized strength in civilian employees of a department or agency from which employees are transferred under this section is reduced by the number of employees so transferred. The authorized strength in civilian employees of a department or agency to which employees are transferred under this section is increased by the number of employees so transferred.