Question: whats the new nucluar weapon that is own by britian?

Hywel Owen answered on 17 Jun 2012:

Britain’s nuclear deterrent is called Trident, and has been in service since 1994. It replaced the original Polaris system. Both are missiles launched from submarines: the idea is that putting the submarines means that an opponent can’t destroy them before they are fired, and missiles are the only effective means of delivery in modern warfare.

Of course, nuclear weapons are hugely controversial, and it’s an interesting question who the ‘opponent’ is supposed to be. In the past this was Soviet Russia, but now it’s harder to argue really who it is.