Over at Libertarian Musings they asked why on earth we need to replace Trident as the deterrent will never be used. The answer is simple.
Its basic anthropology, you see it is not about security, its about status. In the world of big time politics your status depends on the size of your weapon.
Now Bush has the biggest nuclear arsenal, check out that walk. Shoulders back, arms spread, hips thrust forward, he's saying "oi, shut your mouth and look at the size of my weapon."
Blair can't match him of course but he still wants to walk wih a bit of a swagger so he needs a decent sized weapon to show off.
The leaders of nations like Luxembourg of couse just have to creep around with bowed heads and hunched shoulders hoping nobody notices them.
Its all very paleolithic in nature. Of course evolution and wearing trousers has deprived our leaders of the ability to grow big red arses so they have to do the next best thing