Economies of Scale
Direct quote from last weeks the Now Show:
"Nuclear weapons are hideously expensive and can never be used, but as Churchill said 'its the price we pay to sit at the top table.'
Which is ironic, given the arguments the government encounters when trying to convince kids not to carry knives:
'Come on UK, we're having a nuclear weapons amnesty, hand them in."
"Nah man, these weapons get me respect innit."
"But if you use them people might get hurt."
"Has france handed theirs in?"
"Well... Not exacty,"
"Then you'd best get out my face old man, before you get bruck up."
http://www.bbc.co.uk/iplayer/episode/b00jjtz1/The_Now_Show_Series_26_Episode_6/
Give it a listen, its a good one.