There is ample evidence that U.S. airlines outsource much of their maintenance to inferior, uncertified, foreign maintenance facilities with little U.S. oversight. Many pilots (and other people) feel that this kind of on-the-cheap risk is the kind of thing responsible for the two pretty-recent Boeing 737-MAX crashes.
There is currently a bill in congress called HR 5119 (the Safe Aircraft Maintenance Standards Act). Its main job is to help ensure that the U.S. does provide significant oversight for foreign-performed maintenance on our airliners.
If you want to dig into the details, go to https://www.govtrack.us/congress/bills/116/hr5119. There is a button near the top of the page that helps you call or write your congresspeople. Alternately, please contact your representatives via congress.gov/members and stress to them that you want them to support HR 5119.
This kind of thing could truly save lives.