The Great Debate UK
from UK News:
The four Vanguard class submarines which make up what is left of the UK deterrent come to the end of their lives around 2019 and their Trident missiles will need updating in the 2020s.
The go-ahead for replacement, which will cost some 20 billion pounds, was given by Tony Blair in 2006.
Cheaper alternatives, like having a ballistic missile system or a plane-delivered bomb or cutting the number of subs to three have been mulled over the last few years.