ST. MARYS, Ga. — Navy officials call the replacement of Ohio-class submarines home-ported at Naval Submarine Base Kings Bay and at the Pacific base in Bangor, Wash., the service’s “top priority program.”

And if it means scrapping air and land nuclear weapon delivery systems to replace the fleet, then so be it, according to a study by the Cato Institute, a public policy think tank that conducts independent, nonpartisan research on a wide range of policy issues.