"These dangers are inherent whilst the British government maintains its 1960s policy of having at least one nuclear weapons submarine sailing round the Atlantic 24 hours a day, 365 days a year," she said.
A cheaper solution in which British submarines sailed from French or American bases has practical difficulties (and would make the claim of independent control perhaps conclusively unsustainable).
On Sunday, in a show of the allies' military power, a fleet of American and South Korean ships and submarines sailed into waters off the east coast of South Korea, led by the nuclear-powered aircraft carrier George Washington, one of the biggest ships in the United States Navy.
Halsey's plans included the use of battleships and cruisers to bombard military facilities and factories, and in preparation for these attacks US Navy submarines sailed into inshore waters to search for naval mines.
The alternative seemed hardly less daring: using a helicopter to lift the wounded man and his stretcher out of a hatch on the top of the submarine's sail.
These are sensor systems that, like the periscope, project upward to the surface from the submarine's sail; however, unlike the periscope, they relay optical, infrared, and radiowave information to the control room electronically, without the need for any hardware to pierce the submarine's hull.
Fearing that the message had been monitored by the Italians and that the submarine might sail into a trap, the decision was made by senior officers not to send it to the rendezvous point.
However, Park Suk Kyun, a North Korea expert at the Freedom League in Seoul, called the government suggestion that the sub was not on a spy mission "a sheer lie". "That submarine can sail only 140 km [87 miles] without the help of a mother vessel," Park said.
In June a missile-carrying Israeli submarine ostentatiously sailed through the Suez Canal.
The submarine then sailed for the Siberian continental shelf, where it began its mission of secret reconnaissance.
