Once the Army had the job of coastal defense on American soil. I even have a photocopy of a turn-of-the-last century Army rule book on simulating coastal defense with tabletop set-ups. So this isn't completely alien:
Amidst invitees such as the Vietnamese People’s Navy and the Tongan Maritime Force, arguably the most exotic invitees to the 2018 [RIMPAC] sea-warfare gala was a rocket artillery unit from the U.S. Army’s 17th Field Artillery Brigade.
That year’s exercise climaxed with the seemingly ritualistic sinking of the retired Navy Landing Ship Tank USS Racine, which was battered with torpedoes, missiles—and Army artillery.
Rockets guided by drone spotters were the Army contribution.
I noted that exercise.
That's fine. But I think that dedicated land-based coastal artillery should be provided by the Navy's ground force and the Marines.
And more broadly, multi-domain operations shouldn't compromise the core missions of the services in their own domain as they strive to operate across all domains.
