Why not just change the interpretation of the FARs' to state that no domestic US 121 Carrier by Air is allowed to utilize any maintenance provider that does not allow free and unfettered inspection by the US Government Agencies authorized to insure compliance with the same rules applicable to domestic MRO providers with respect to Air Carrier Operations and Maintenance, Certification, Safety, Environmental and Security regulations?
As of now: foreign providers of MRO requirements to domestic US 121 Air Carriers are being allowed to use their local rules without respect to US Air Carrier regulations for the safety, environmental and security requirements placed on US Domestic MRO Operations and are not subject to free and fettered inspection from the US Government and US Government Inspection of foreign MRO providers is regulated by the host country, not by the FAA issued 121 Air Carrier Certificate which authorizes domestic flight operations.
Simply changing the interpretation of authorized maintenance for US certificated 121 Air Carriers to require that any and all of their maintenance requirements are conducted in accordance with all the applicable US domestic MRO operations ewould allow the imposition by the US Government of the same standards met by domestic MRO providers and full, free, unfettered inspection of those facilities to insure compliance.