The U.S. Navy must, in particular, retain the capability to deter the use of naval nuclear arms against its fleet.

CENTERFORSECURITYPOLICY: Center for Security Policy | A Scorecard On The Defense Budget: Preserving Key Priorities And Programs In An Era Of Cuts

"Piggy-backing on a large U-boat, the Seehund had the capability of reaching the Foyle where there was intense naval and merchant navy activity, " he said.

BBC: Experts to examine River Foyle, Derry, wreck

Chief of Naval Operations Admiral Jonathan Greenert argued in a recent article for increased investments in developing advanced payloads to enhance the capability of legacy platforms to counter advanced threats.

CENTERFORSECURITYPOLICY: Section IV: Building a Two-MRC Force for the 21st Century