Does it though, or is this a false sense of security? Regardless of the Jones Act the Navy is paying to modernize shipyards [0]. Meanwhile the small shipping industry propped up by the Jones Act seems to severely outdated, they were using steamships well past when the rest of the world stopped using them and manage to get away with more corruption due to lack of competition [1]. Maybe just drop the act, and have the Navy responsible for shipyards directly & ongoing, or something rather than hope a bunch of old fashioned, inefficient shipyards will be sufficient when we need them most?
https://www.gao.gov/products/gao-22-105993
https://www.freightwaves.com/news/freightwaves-classicsfalle...
Jone's Act doesn't protect any shipbuilding facility, beyond the existing government contracts forwarded to them.
Something that actually resulted in productive shipyards would be much better than what we have that results in shipyards that don't produce much, which is still likely better than no shipyards outside of those producing naval vessels and domestic ferries (although, those would probably be imported too, if that were legal; technically that's prohibited under a different act)
It also strikes me that the percentages mentioned in the article are very high. 75% US crew? 75% US owned? 100% US built? Revising the statute to operators needing 55% of their domestic fleet being US built, and requiring 55% US ownership, and a 55% US crew should be more than sufficient. Give tax incentives for newer, more efficient craft both to the manufacturer and the buyer.
The US uses a lot of military power for non-combat purposes. We move supplies for natural and humanitarian disasters. We have water purification ships, hospital ships, and generator ships. We transport weapons systems as cargo, and even those ships themselves could be mostly protected by a surrounding fleet. If we could get a design made that's fitting for heavy movers suitable for both military and civilian use the US government's purchases could bolster domestic shippers' orders.
One even more unusual option since it's a national security concern is the US government could buy large numbers of newer, more efficient craft and lease them on affordable terms (or lease to own even) to cargo companies.
https://www.freightwaves.com/news/freightwaves-classics-amer....
China does not have its own version of the Jones act, it's a uniquely American problem. Most countries aren't stupid enough to kill their internal industry.
If having any local shipbuilding capability is better than none, the act works enough.
IMHO, I'd drop Puerto Rico and other island territories from the act. Maybe Hawaii and Alaska too. The inducement to build and operate US based cargo ships for those markets clearly isn't sufficient, and it hurts the economy of the territories for little benefit. But keep it for the mainland --- I think effectively reserving US ports for foreign trade reduces import/export costs which helps the US interface with the global market.