my very, very cunning plan to replace Trident ... is it flawlesss, wise forumites??

Why doesn't the Government buy a house or two in the countries where we think we would need to fire a nuclear missile.  House should be near where we would be targetting with a missile if ever we wanted to fire one. We send foreign office diplomats to live there as part of their normal job.  Unbeknown to them we build in a nuclear bomb - say hidden in the cellar.  Bomb can be armed remotely.

I think you will all agree that this is indeed a cunning plan.

And comparatively cheap compared with Trident.

Maybe the Iranians, N Koreans et al have already done it over here.