; or (B) conditions of environment that— (i) differ substantially from conditions of environment in the continental United States; and (ii) warrant an allowance as a recruitment incentive. (3) An allowance under this subsection may not exceed the allowance authorized to be paid by section 5941(a) of title 5 for employees whose rates of basic pay are fixed by statute. 9379. Limitation on certain payments No allowance, differential, bonus, award, or other similar cash payment under this title may be paid to an employee in a calendar year if, or to the extent that, when added to the total basic pay paid or payable to such employee for service performed in such calendar year, such payment would cause the total to exceed the total annual compensation payable to the Vice President under section 104 of title 3 as of the end of such calendar year. 9380. Benefits for certain employees assigned outside the United States (a) In general The Secretary of Defense may provide to civilian personnel described in subsection (c) allowances and benefits comparable to those provided by the Secretary of State to officers and employees of the Foreign Service under paragraphs (2) through (8) and (13) of section 901 and sections 705 and 903 of the Foreign Service Act of 1980 ( 22 U.S.C. 4081 (2), (3), (4), (5), (6), (7), (8), and (13), 4025, 4083) and under section 5924(4) of title 5. (b) Applicability Subsection (a) shall apply to civilian personnel of the Department of Defense who— (1) are United States nationals; (2) are assigned to duty outside the United States