Sharing procurement of nuclear weapons delivery systems makes simple sense through sharing the cost. The UK only contributed 5% of the original cost of trident but the UK systems are just as potent. This however does not mean that the UK weapons systems are not independent. Operationally the UK has complete control over its weapons. The USA cannot in any way prevent, veto or forbid the UK from using its own nuclear weapons. [1] It is independent in the way that matters.  [1] Directorate of Chemical, Biological, Radiological and Nuclear Policy, ‘Your freedom of information request about the UK Nuclear deterrent’, 19 July 2005.