John F. Frittelli, Congressional Research Service Report RS21566 "The Jones Act…
“ Although in peacetime the Jones Act may be viewed by many as an anachronism, in wartime, shipbuilding and a merchant marine are viewed as vital to national security. Defense groups argue that the maritime community represents a highly skilled work force and a physical establishment that can not be quickly replaced once it is lost. They assert that the national security importance of the Jones Act goes beyond the simple "bean counting" of deep-sea vessels. The most valuable national security component that the Jones Act provides, they contend, is a domestic shipbuilding and repair base. ”
