Cargo moving between U.S. ports must travel on ships that are American-built, -flagged, -owned and -crewed, under Section 27 of the 1920 Merchant Marine Act, known as the Jones Act. The episode argues it both ways: a national-defense guarantee for shipyards and citizen crews, or a costly protection that hit Puerto Rico, Hawaii and Alaska hardest and failed to save the fleet it was meant to preserve.
Estimates of the Act's cost range widely, from about $200 million a year to far higher academic figures. Critics blame the Act for the fleet's decline while defenders point to global competition, and whether repeal would help or hollow out national security is unresolved.



