It's been 50 years since nuclear submarines first came to Scotland. But the Trident fleet is ageing, and the contentious decision to start work on its replacement has been delayed until 2016.
Presented by Sally Magnusson and partly filmed on board one of Britain's nuclear bomber submarines, 'Who Needs Trident?' asks whether a Cold War weapon, designed to deter the Soviet Union from attacking Britain and its NATO allies, is still relevant in the 21st century, and whether Britain, and Scotland, gain anything from it being replaced.
