In the story, it says "AMFELS is a subsidiary of Keppel Offshore & Marine, Ltd. of Singapore, which makes about 60 percent of the world's jack-up oil rigs"; I don't believe that Singaporean companies care at all about American jobs or American security.
You will find the same is true with American companies in other countries; they are not there to worry about the locals' employment conditions or the foreign country's security. They are there to make money from a business opportunity, and generally have no loyalty or other greater interest in the area. (Yes, I know that there are exceptions, but I cannot even think of one at present.)
Says: Keppel Offshore & Marine (AMFELS), Brownsville TX
Record of Post-WWII Shipbuilding
Marathon LeTourneau's Brownsville shipyard was sold to local interests in the early 1990s and then sold again to Keppel FELS (now Keppel Offshore & Marine) which renamed it AMFELS and re-entered the rigbuilding business.
Doesn't give dates for last company turnover though.