I do not believe that Amerika even has the infrastructure to self-source all the necessary components to 1) build entire ships 2) manufacture the necessary munitions it would require. That carries over to all branches of the military.
The Amerikan economy has been downgraded to the point where we could not fight a real war. We don’t have the chips, factories, infrastructure to support a military in the field for very long (using existing stockpiles) and the time it takes to create the infrastructure is lengthy and a major war would be lost before they could come online even assuming our factories and infrastructure were left unmolested by an enemy.