((a)) ** Civil Service and Foreign Service Retirement Systems** In order to maintain existing conformity between the Civil Service Retirement and Disability System under subchapter III of chapter 83 of title 5, and the Foreign Service Retirement and Disability System, whenever a law of general applicability is enacted which—

((1)) affects the treatment of current or former participants, annuitants, or survivors under the Civil Service Retirement and Disability System; and

((2)) affects treatment which, immediately prior to the enactment of such law, was substantially identical to the treatment accorded to participants, former participants, annuitants, or survivors under the Foreign Service Retirement and Disability System;

((b)) ** Regulations to implement prescribed by Executive order** The President shall by Executive order prescribe regulations to implement this section and may make such extension retroactive to a date no earlier than the effective date of the provision of law applicable to the Civil Service Retirement and Disability System. Any provision of an Executive order issued under this section shall modify, supersede, or render inapplicable, as the case may be, to the extent inconsistent therewith—

((1)) all provisions of law enacted prior to the effective date of that provision of the Executive order, and

((2)) any prior provision of an Executive order issued under this section.

((c)) ** Federal Employees’ Retirement and Foreign Service Pension Systems** The President shall maintain, under the same conditions and in the same manner as provided in subsections (a) and (b) existing conformity between the Federal Employees’ Retirement System provided in chapter 84 of title 5 and the Foreign Service Pension System provided in part II of this subchapter.